diff --git a/frontend/src/components/ai/AIBuiltinToolsCatalog.test.tsx b/frontend/src/components/ai/AIBuiltinToolsCatalog.test.tsx
index a7b5e0b..37f3f83 100644
--- a/frontend/src/components/ai/AIBuiltinToolsCatalog.test.tsx
+++ b/frontend/src/components/ai/AIBuiltinToolsCatalog.test.tsx
@@ -66,6 +66,8 @@ describe('AIBuiltinToolsCatalog', () => {
     expect(markup).toContain('inspect_recent_sql_activity');
     expect(markup).toContain('排查应用日志');
     expect(markup).toContain('inspect_app_logs');
+    expect(markup).toContain('排查连接失败与冷却');
+    expect(markup).toContain('inspect_recent_connection_failures');
     expect(markup).toContain('排查 AI 气泡渲染异常');
     expect(markup).toContain('inspect_ai_last_render_error');
     expect(markup).toContain('复用历史 SQL');
diff --git a/frontend/src/components/ai/AIBuiltinToolsCatalog.tsx b/frontend/src/components/ai/AIBuiltinToolsCatalog.tsx
index c596d7c..c071e4f 100644
--- a/frontend/src/components/ai/AIBuiltinToolsCatalog.tsx
+++ b/frontend/src/components/ai/AIBuiltinToolsCatalog.tsx
@@ -140,6 +140,11 @@ const BUILTIN_TOOL_FLOWS = [
     steps: 'inspect_app_logs → inspect_mcp_setup / inspect_saved_connections / inspect_current_connection',
     description: '适合先回看 gonavi.log 尾部的 ERROR/WARN，再结合 MCP、连接和当前数据源状态继续定位启动异常、连接失败或外部工具拉起问题。',
   },
+  {
+    title: '排查连接失败与冷却',
+    steps: 'inspect_recent_connection_failures → inspect_current_connection / inspect_saved_connections / inspect_app_logs',
+    description: '适合用户直接问“为什么连接不上”或已经看到冷却/验证失败提示时，先拿到结构化根因、最新地址和下一步建议，再决定回到连接配置还是看更长日志。',
+  },
   {
     title: '排查 AI 气泡渲染异常',
     steps: 'inspect_ai_last_render_error → inspect_active_tab / inspect_ai_runtime',
diff --git a/frontend/src/components/ai/aiConnectionFailureInsights.test.ts b/frontend/src/components/ai/aiConnectionFailureInsights.test.ts
new file mode 100644
index 0000000..1678aa5
--- /dev/null
+++ b/frontend/src/components/ai/aiConnectionFailureInsights.test.ts
@@ -0,0 +1,67 @@
+import { describe, expect, it } from 'vitest';
+
+import { buildRecentConnectionFailureSnapshot } from './aiConnectionFailureInsights';
+
+describe('buildRecentConnectionFailureSnapshot', () => {
+  it('summarizes recent validation failures and cooldown hits from gonavi.log lines', () => {
+    const snapshot = buildRecentConnectionFailureSnapshot({
+      readResult: {
+        success: true,
+        data: {
+          logPath: 'C:/Users/demo/.GoNavi/Logs/gonavi.log',
+          requestedLineLimit: 120,
+          lines: [
+            '2026/06/06 19:42:36.037552 [INFO] 获取数据库连接：类型=mysql 地址=10.188.101.184:1523 数据库=(default) 用户=glzc 超时=30s 拓扑=single SSH=192.168.66.28:22 用户=wyeye 缓存Key=026837d0a1b6 启动阶段=稳定期(age=34.322s)',
+            '2026/06/06 19:42:37.088288 [ERROR] 建立数据库连接失败：类型=mysql 地址=10.188.101.184:1523 数据库=(default) 用户=glzc 超时=30s 拓扑=single SSH=192.168.66.28:22 用户=wyeye 缓存Key=026837d0a1b6；错误链：连接建立后验证失败：10.188.101.184:1523 验证失败: Error 10004 (HY000): Parametric information is abnormal.（详细日志：C:/Users/demo/.GoNavi/Logs/gonavi.log） -> 连接建立后验证失败：10.188.101.184:1523 验证失败: Error 10004 (HY000): Parametric information is abnormal.',
+            '2026/06/06 19:42:37.094045 [ERROR] DBGetDatabases 获取连接失败：类型=mysql 地址=10.188.101.184:1523 数据库=(default) 用户=glzc 超时=30s 拓扑=single SSH=192.168.66.28:22 用户=wyeye；错误链：连接建立后验证失败：10.188.101.184:1523 验证失败: Error 10004 (HY000): Parametric information is abnormal.（详细日志：C:/Users/demo/.GoNavi/Logs/gonavi.log） -> 连接建立后验证失败：10.188.101.184:1523 验证失败: Error 10004 (HY000): Parametric information is abnormal.',
+            '2026/06/06 19:42:37.101316 [WARN] 命中数据库连接失败冷却：类型=mysql 地址=10.188.101.184:1523 数据库=(default) 用户=glzc 超时=30s 拓扑=single SSH=192.168.66.28:22 用户=wyeye 缓存Key=026837d0a1b6 剩余=29s 原因=连接建立后验证失败：10.188.101.184:1523 验证失败: Error 10004 (HY000): Parametric information is abnormal.（详细日志：C:/Users/demo/.GoNavi/Logs/gonavi.log）',
+          ],
+        },
+      },
+    });
+
+    expect(snapshot.failureEventCount).toBe(3);
+    expect(snapshot.primaryCategory).toBe('parameter_compatibility');
+    expect(snapshot.cooldownHitCount).toBe(1);
+    expect(snapshot.addresses[0]?.address).toBe('10.188.101.184:1523');
+    expect(snapshot.latestFailure?.cooldownSeconds).toBe(29);
+    expect(snapshot.nextActions.join('\n')).toContain('multiStatements');
+  });
+
+  it('recognizes mysql compatibility fallback syntax errors as parameter or compatibility issues', () => {
+    const snapshot = buildRecentConnectionFailureSnapshot({
+      readResult: {
+        success: true,
+        data: {
+          logPath: 'C:/Users/demo/.GoNavi/Logs/gonavi.log',
+          lines: [
+            '2026/06/07 15:50:35.000000 [ERROR] DBGetDatabases 获取连接失败：类型=mysql 地址=127.0.0.1:48749 数据库=(default) 用户=root；错误链：连接最近失败，正在冷却中，请 29s 后重试；上次错误：连接建立后验证失败：127.0.0.1:48749 [默认兼容参数] 验证失败: Error 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'%2Cutf8\' at line 1；127.0.0.1:48749 [禁用 multiStatements 兼容重试] 验证失败: Error 1064 (42000): You have an error in your SQL syntax; check the manual that corresponds to your MySQL server version for the right syntax to use near \'%2Cutf8\' at line 1',
+          ],
+        },
+      },
+    });
+
+    expect(snapshot.failureEventCount).toBe(1);
+    expect(snapshot.primaryCategory).toBe('parameter_compatibility');
+    expect(snapshot.recentFailures[0]?.rootCause).toContain('%2Cutf8');
+    expect(snapshot.nextActions.join('\n')).toContain('连接参数');
+  });
+
+  it('returns an empty-state message when the tail has no connection-related failures', () => {
+    const snapshot = buildRecentConnectionFailureSnapshot({
+      readResult: {
+        success: true,
+        data: {
+          logPath: 'C:/Users/demo/.GoNavi/Logs/gonavi.log',
+          lines: [
+            '2026/06/09 10:00:00.000000 [INFO] started',
+            '2026/06/09 10:00:01.000000 [INFO] ai ready',
+          ],
+        },
+      },
+    });
+
+    expect(snapshot.failureEventCount).toBe(0);
+    expect(snapshot.message).toContain('没有识别到连接失败');
+  });
+});
diff --git a/frontend/src/components/ai/aiConnectionFailureInsights.ts b/frontend/src/components/ai/aiConnectionFailureInsights.ts
new file mode 100644
index 0000000..17ad271
--- /dev/null
+++ b/frontend/src/components/ai/aiConnectionFailureInsights.ts
@@ -0,0 +1,412 @@
+const DEFAULT_CONNECTION_FAILURE_LOG_LIMIT = 120;
+const MAX_CONNECTION_FAILURE_LOG_LIMIT = 240;
+const MAX_RECENT_FAILURES = 8;
+
+type ConnectionFailureCategory =
+  | 'cooldown'
+  | 'parameter_compatibility'
+  | 'validation'
+  | 'authentication'
+  | 'timeout'
+  | 'network'
+  | 'ssh'
+  | 'startup'
+  | 'other';
+
+type ConnectionFailureEventType =
+  | 'connection_failure'
+  | 'connection_operation_failure'
+  | 'cooldown_hit'
+  | 'ssh_failure';
+
+interface ConnectionFailureEvent {
+  rawLine: string;
+  timestamp: string;
+  level: string;
+  eventType: ConnectionFailureEventType;
+  category: ConnectionFailureCategory;
+  categoryLabel: string;
+  connectionType: string;
+  address: string;
+  dbName: string;
+  sshAddress: string;
+  rootCause: string;
+  cooldownSeconds: number | null;
+}
+
+const CONNECTION_FAILURE_CATEGORY_LABELS: Record<ConnectionFailureCategory, string> = {
+  cooldown: '冷却重试',
+  parameter_compatibility: '连接参数/兼容性',
+  validation: '连接验证失败',
+  authentication: '认证失败',
+  timeout: '连接超时',
+  network: '网络不可达',
+  ssh: 'SSH 隧道失败',
+  startup: '驱动/进程启动失败',
+  other: '其他连接异常',
+};
+
+const normalizeLogLines = (input: unknown): string[] =>
+  Array.isArray(input)
+    ? input.map((line) => String(line || '').trim()).filter(Boolean)
+    : [];
+
+const normalizeConnectionFailureLimit = (input: unknown): number => {
+  const value = Math.floor(Number(input) || DEFAULT_CONNECTION_FAILURE_LOG_LIMIT);
+  if (value < 1) {
+    return 1;
+  }
+  if (value > MAX_CONNECTION_FAILURE_LOG_LIMIT) {
+    return MAX_CONNECTION_FAILURE_LOG_LIMIT;
+  }
+  return value;
+};
+
+const extractLogTimestamp = (line: string): string => {
+  const match = String(line || '').match(/^(\d{4}\/\d{2}\/\d{2}\s+\d{2}:\d{2}:\d{2}(?:\.\d+)?)/);
+  return match?.[1] || '';
+};
+
+const extractLogLevelAndPayload = (line: string) => {
+  const match = String(line || '').match(/\[(INFO|WARN|ERROR)\]\s*(.*)$/);
+  if (match) {
+    return {
+      level: match[1],
+      payload: String(match[2] || '').trim(),
+    };
+  }
+  return {
+    level: 'OTHER',
+    payload: String(line || '').trim(),
+  };
+};
+
+const extractField = (payload: string, field: string): string => {
+  const match = payload.match(new RegExp(`${field}=([^\\s]+)`));
+  return String(match?.[1] || '').trim();
+};
+
+const extractAddressCandidates = (text: string): string[] => {
+  const matches = text.match(/\b(?:\d{1,3}(?:\.\d{1,3}){3}|localhost|[A-Za-z0-9._-]+):\d+\b/g);
+  return Array.isArray(matches) ? Array.from(new Set(matches)) : [];
+};
+
+const sanitizeRootCause = (value: string): string =>
+  String(value || '')
+    .replace(/（详细日志：[^）]+）/g, '')
+    .replace(/\s+/g, ' ')
+    .replace(/\s*->\s*/g, ' -> ')
+    .trim();
+
+const extractRootCause = (payload: string): string => {
+  const errorChainIndex = payload.indexOf('错误链：');
+  if (errorChainIndex >= 0) {
+    return sanitizeRootCause(payload.slice(errorChainIndex + '错误链：'.length));
+  }
+
+  const reasonIndex = payload.indexOf('原因=');
+  if (reasonIndex >= 0) {
+    return sanitizeRootCause(payload.slice(reasonIndex + '原因='.length));
+  }
+
+  const cooldownIndex = payload.indexOf('连接最近失败，正在冷却中');
+  if (cooldownIndex >= 0) {
+    return sanitizeRootCause(payload.slice(cooldownIndex));
+  }
+
+  const sshFailureIndex = payload.indexOf('SSH 连接建立失败：');
+  if (sshFailureIndex >= 0) {
+    return sanitizeRootCause(payload.slice(sshFailureIndex + 'SSH 连接建立失败：'.length));
+  }
+
+  const validationIndex = payload.indexOf('连接建立后验证失败：');
+  if (validationIndex >= 0) {
+    return sanitizeRootCause(payload.slice(validationIndex));
+  }
+
+  return sanitizeRootCause(payload);
+};
+
+const extractCooldownSeconds = (payload: string, rootCause: string): number | null => {
+  const target = `${payload} ${rootCause}`;
+  const match = target.match(/(?:剩余=|请\s*)(\d+)s(?:\s*后重试)?/);
+  if (!match) {
+    return null;
+  }
+  const value = Number(match[1]);
+  return Number.isFinite(value) ? value : null;
+};
+
+const inferConnectionFailureCategory = (
+  payload: string,
+  rootCause: string,
+): ConnectionFailureCategory => {
+  const text = `${payload} ${rootCause}`;
+  const lowerText = text.toLowerCase();
+  const errorText = rootCause || payload;
+  const lowerErrorText = errorText.toLowerCase();
+
+  if (
+    text.includes('SSH 连接建立失败')
+    || /ssh\s+(dial|handshake|tunnel)/i.test(text)
+    || /ssh.*(认证失败|连接失败|超时)/i.test(text)
+  ) {
+    return 'ssh';
+  }
+  if (
+    lowerErrorText.includes('connect timeout')
+    || lowerErrorText.includes('i/o timeout')
+    || lowerErrorText.includes('deadline exceeded')
+    || errorText.includes('连接超时')
+    || /超时(?!\=)/.test(errorText)
+  ) {
+    return 'timeout';
+  }
+  if (
+    lowerText.includes('access denied')
+    || lowerText.includes('authentication failed')
+    || lowerText.includes('password')
+    || text.includes('凭据')
+    || text.includes('认证')
+    || text.includes('登录失败')
+  ) {
+    return 'authentication';
+  }
+  if (
+    lowerText.includes('parametric information is abnormal')
+    || lowerText.includes('error 1064')
+    || lowerText.includes('%2cutf8')
+    || lowerText.includes('multistatements')
+    || text.includes('兼容参数')
+    || lowerText.includes('syntax')
+    || lowerText.includes('dsn')
+    || text.includes('参数')
+  ) {
+    return 'parameter_compatibility';
+  }
+  if (text.includes('验证失败')) {
+    return 'validation';
+  }
+  if (
+    lowerText.includes('connection refused')
+    || lowerText.includes('dial tcp')
+    || lowerText.includes('no route')
+    || lowerText.includes('network is unreachable')
+    || lowerText.includes('refused')
+  ) {
+    return 'network';
+  }
+  if (lowerText.includes('spawn') || text.includes('启动失败') || text.includes('拉起失败')) {
+    return 'startup';
+  }
+  if (text.includes('冷却')) {
+    return 'cooldown';
+  }
+  return 'other';
+};
+
+const detectConnectionFailureEventType = (payload: string): ConnectionFailureEventType | null => {
+  if (payload.includes('命中数据库连接失败冷却：') || payload.includes('连接最近失败，正在冷却中')) {
+    return 'cooldown_hit';
+  }
+  if (payload.includes('SSH 连接建立失败：')) {
+    return 'ssh_failure';
+  }
+  if (payload.includes('建立数据库连接失败：')) {
+    return 'connection_failure';
+  }
+  if (/DB[A-Za-z0-9_]+\s+获取连接失败：/.test(payload)) {
+    return 'connection_operation_failure';
+  }
+  return null;
+};
+
+const buildConnectionFailureEvent = (line: string): ConnectionFailureEvent | null => {
+  const timestamp = extractLogTimestamp(line);
+  const { level, payload } = extractLogLevelAndPayload(line);
+  const eventType = detectConnectionFailureEventType(payload);
+  if (!eventType) {
+    return null;
+  }
+
+  const rootCause = extractRootCause(payload);
+  const extractedType = extractField(payload, '类型');
+  const extractedAddress = extractField(payload, '地址');
+  const addressCandidates = extractAddressCandidates(rootCause);
+  const address = extractedAddress || addressCandidates[0] || '';
+  const category = inferConnectionFailureCategory(payload, rootCause);
+
+  return {
+    rawLine: line,
+    timestamp,
+    level,
+    eventType,
+    category,
+    categoryLabel: CONNECTION_FAILURE_CATEGORY_LABELS[category],
+    connectionType: extractedType,
+    address,
+    dbName: extractField(payload, '数据库'),
+    sshAddress: extractField(payload, 'SSH'),
+    rootCause,
+    cooldownSeconds: extractCooldownSeconds(payload, rootCause),
+  };
+};
+
+const appendUnique = (items: string[], value: string) => {
+  const normalized = String(value || '').trim();
+  if (!normalized || items.includes(normalized)) {
+    return;
+  }
+  items.push(normalized);
+};
+
+const buildNextActions = (events: ConnectionFailureEvent[]): string[] => {
+  const categories = new Set(events.map((event) => event.category));
+  const hasCooldownEvent = events.some((event) => event.eventType === 'cooldown_hit');
+  const nextActions: string[] = [];
+  const latestEvent = events[events.length - 1];
+
+  if (hasCooldownEvent || categories.has('cooldown')) {
+    appendUnique(nextActions, '先修复上一次真实连接错误，再重试；只反复刷新会持续命中连接冷却。');
+  }
+  if (categories.has('parameter_compatibility')) {
+    appendUnique(nextActions, '优先核对连接参数、DSN 和协议兼容性，尤其是 multiStatements、charset、额外 query 参数和 URL 编码。');
+  }
+  if (categories.has('validation')) {
+    appendUnique(nextActions, '检查服务端返回的验证失败细节，确认当前数据库类型、驱动协议、库名或 Service Name 与目标服务匹配。');
+  }
+  if (categories.has('authentication')) {
+    appendUnique(nextActions, '核对用户名、密码、认证库、租户或 Service Name 是否正确，确认服务端是否允许当前账号登录。');
+  }
+  if (categories.has('ssh')) {
+    appendUnique(nextActions, '核对 SSH 跳板机地址、端口、账号和隧道目标地址，必要时先验证跳板机到数据库的连通性。');
+  }
+  if (categories.has('timeout') || categories.has('network')) {
+    appendUnique(nextActions, '检查目标地址、端口、防火墙、代理和隧道链路是否可达，确认服务端当前确实在监听。');
+  }
+  if (categories.has('startup')) {
+    appendUnique(nextActions, '检查驱动进程或外部依赖是否能正常启动，必要时先在本机或目标主机单独验证启动命令。');
+  }
+  if (latestEvent?.address) {
+    appendUnique(nextActions, `如需核对当前界面里的连接是否还是同一目标，可再调用 inspect_current_connection 检查是否仍指向 ${latestEvent.address}。`);
+  }
+  if (nextActions.length === 0) {
+    appendUnique(nextActions, '先结合 inspect_current_connection 和 inspect_saved_connections 核对当前连接配置，再扩大日志窗口继续排查。');
+  }
+  return nextActions;
+};
+
+export const buildRecentConnectionFailureSnapshot = (params: {
+  readResult?: any;
+  keyword?: unknown;
+  lineLimit?: unknown;
+}) => {
+  const data = params.readResult?.data && typeof params.readResult.data === 'object'
+    ? params.readResult.data as Record<string, unknown>
+    : {};
+  const lines = normalizeLogLines(data.lines);
+  const keyword = String(data.keyword || params.keyword || '').trim();
+  const requestedLineLimit = normalizeConnectionFailureLimit(data.requestedLineLimit ?? params.lineLimit);
+  const events = lines
+    .map((line) => buildConnectionFailureEvent(line))
+    .filter((event): event is ConnectionFailureEvent => Boolean(event));
+  const latestEvent = events[events.length - 1];
+
+  const categoryCounts = new Map<ConnectionFailureCategory, number>();
+  const addressCounts = new Map<string, { count: number; connectionTypes: Set<string>; lastSeenAt: string }>();
+  events.forEach((event) => {
+    categoryCounts.set(event.category, (categoryCounts.get(event.category) || 0) + 1);
+    if (!event.address) {
+      return;
+    }
+    const current = addressCounts.get(event.address) || {
+      count: 0,
+      connectionTypes: new Set<string>(),
+      lastSeenAt: '',
+    };
+    current.count += 1;
+    if (event.connectionType) {
+      current.connectionTypes.add(event.connectionType);
+    }
+    current.lastSeenAt = event.timestamp || current.lastSeenAt;
+    addressCounts.set(event.address, current);
+  });
+
+  const categorySummary = Array.from(categoryCounts.entries())
+    .sort((left, right) => right[1] - left[1])
+    .map(([category, count]) => ({
+      category,
+      label: CONNECTION_FAILURE_CATEGORY_LABELS[category],
+      count,
+    }));
+  const primaryCategory = categorySummary[0]?.category || '';
+
+  const addresses = Array.from(addressCounts.entries())
+    .sort((left, right) => right[1].count - left[1].count)
+    .map(([address, summary]) => ({
+      address,
+      count: summary.count,
+      connectionTypes: Array.from(summary.connectionTypes),
+      lastSeenAt: summary.lastSeenAt,
+    }));
+
+  return {
+    logPath: String(data.logPath || ''),
+    keyword,
+    requestedLineLimit,
+    returnedLineCount: lines.length,
+    fileWindowTruncated: data.fileWindowTruncated === true,
+    matchedLinesTruncated: data.matchedLinesTruncated === true,
+    failureEventCount: events.length,
+    hasRecentFailures: events.length > 0,
+    primaryCategory,
+    primaryCategoryLabel: primaryCategory
+      ? CONNECTION_FAILURE_CATEGORY_LABELS[primaryCategory as ConnectionFailureCategory]
+      : '',
+    cooldownHitCount: events.filter((event) => event.eventType === 'cooldown_hit').length,
+    validationFailureCount: events.filter((event) => event.category === 'validation').length,
+    sshFailureCount: events.filter((event) => event.category === 'ssh').length,
+    categorySummary,
+    addresses,
+    latestFailureAt: latestEvent?.timestamp || '',
+    latestFailure: latestEvent
+      ? {
+        timestamp: latestEvent.timestamp,
+        level: latestEvent.level,
+        eventType: latestEvent.eventType,
+        category: latestEvent.category,
+        categoryLabel: latestEvent.categoryLabel,
+        connectionType: latestEvent.connectionType,
+        address: latestEvent.address,
+        dbName: latestEvent.dbName,
+        sshAddress: latestEvent.sshAddress,
+        cooldownSeconds: latestEvent.cooldownSeconds,
+        rootCause: latestEvent.rootCause,
+        rawLine: latestEvent.rawLine,
+      }
+      : null,
+    recentFailures: events
+      .slice(-MAX_RECENT_FAILURES)
+      .reverse()
+      .map((event) => ({
+        timestamp: event.timestamp,
+        level: event.level,
+        eventType: event.eventType,
+        category: event.category,
+        categoryLabel: event.categoryLabel,
+        connectionType: event.connectionType,
+        address: event.address,
+        dbName: event.dbName,
+        sshAddress: event.sshAddress,
+        cooldownSeconds: event.cooldownSeconds,
+        rootCause: event.rootCause,
+        rawLine: event.rawLine,
+      })),
+    nextActions: buildNextActions(events),
+    message: events.length > 0
+      ? `最近日志里识别到 ${events.length} 条连接相关异常，最新一条是 ${latestEvent?.categoryLabel || '连接异常'}`
+      : keyword
+        ? `最近日志里没有找到与“${keyword}”相关的连接失败记录`
+        : '最近日志里没有识别到连接失败、验证失败或连接冷却记录',
+  };
+};
diff --git a/frontend/src/components/ai/aiLocalToolExecutor.connectionFailureInspection.test.ts b/frontend/src/components/ai/aiLocalToolExecutor.connectionFailureInspection.test.ts
new file mode 100644
index 0000000..36f7316
--- /dev/null
+++ b/frontend/src/components/ai/aiLocalToolExecutor.connectionFailureInspection.test.ts
@@ -0,0 +1,52 @@
+import { describe, expect, it, vi } from 'vitest';
+
+import type { AIToolCall } from '../../types';
+import { executeLocalAIToolCall } from './aiLocalToolExecutor';
+
+const buildToolCall = (
+  name: string,
+  args: Record<string, unknown>,
+): AIToolCall => ({
+  id: `call-${name}`,
+  type: 'function',
+  function: {
+    name,
+    arguments: JSON.stringify(args),
+  },
+});
+
+describe('aiLocalToolExecutor inspect_recent_connection_failures', () => {
+  it('returns a structured snapshot for recent connection failures, cooldown hits, and compatibility errors', async () => {
+    const result = await executeLocalAIToolCall({
+      toolCall: buildToolCall('inspect_recent_connection_failures', {
+        keyword: 'mysql',
+        lineLimit: 120,
+      }),
+      connections: [],
+      mcpTools: [],
+      toolContextMap: new Map(),
+      runtime: {
+        getDatabases: vi.fn(),
+        getTables: vi.fn(),
+        readAppLogTail: vi.fn().mockResolvedValue({
+          success: true,
+          data: {
+            logPath: 'C:/Users/demo/.GoNavi/Logs/gonavi.log',
+            keyword: 'mysql',
+            requestedLineLimit: 120,
+            lines: [
+              '2026/06/07 15:50:35.000000 [ERROR] 建立数据库连接失败：类型=mysql 地址=127.0.0.1:48749 数据库=(default) 用户=root；错误链：连接建立后验证失败：127.0.0.1:48749 [默认兼容参数] 验证失败: Error 1064 (42000): You have an error in your SQL syntax near \'%2Cutf8\' at line 1',
+              '2026/06/07 15:50:36.000000 [WARN] 命中数据库连接失败冷却：类型=mysql 地址=127.0.0.1:48749 数据库=(default) 用户=root 剩余=29s 原因=连接建立后验证失败：127.0.0.1:48749 [禁用 multiStatements 兼容重试] 验证失败: Error 1064 (42000): You have an error in your SQL syntax near \'%2Cutf8\' at line 1',
+            ],
+          },
+        }),
+      },
+    });
+
+    expect(result.success).toBe(true);
+    expect(result.content).toContain('"primaryCategory":"parameter_compatibility"');
+    expect(result.content).toContain('"cooldownHitCount":1');
+    expect(result.content).toContain('127.0.0.1:48749');
+    expect(result.content).toContain('multiStatements');
+  });
+});
diff --git a/frontend/src/components/ai/aiSlashCommands.test.ts b/frontend/src/components/ai/aiSlashCommands.test.ts
index d8b8738..57d9cd0 100644
--- a/frontend/src/components/ai/aiSlashCommands.test.ts
+++ b/frontend/src/components/ai/aiSlashCommands.test.ts
@@ -14,6 +14,7 @@ describe('aiSlashCommands', () => {
     expect(commands.some((command) => command.cmd === '/health')).toBe(true);
     expect(commands.some((command) => command.cmd === '/mcp')).toBe(true);
     expect(commands.some((command) => command.cmd === '/mcpadd')).toBe(true);
+    expect(commands.some((command) => command.cmd === '/connfail')).toBe(true);
     expect(commands.some((command) => command.cmd === '/shortcuts')).toBe(true);
     expect(commands.some((command) => command.cmd === '/applog')).toBe(true);
     expect(commands.some((command) => command.cmd === '/airender')).toBe(true);
@@ -31,6 +32,11 @@ describe('aiSlashCommands', () => {
     expect(filterAISlashCommands('/sho').map((command) => command.cmd)).toContain('/shortcuts');
   });
 
+  it('supports filtering connection-failure diagnostics by chinese keyword and command prefix', () => {
+    expect(filterAISlashCommands('连接失败').map((command) => command.cmd)).toContain('/connfail');
+    expect(filterAISlashCommands('/conn').map((command) => command.cmd)).toContain('/connfail');
+  });
+
   it('supports filtering app-log diagnostics by chinese keyword and command prefix', () => {
     expect(filterAISlashCommands('日志').map((command) => command.cmd)).toContain('/applog');
     expect(filterAISlashCommands('/app').map((command) => command.cmd)).toContain('/applog');
@@ -56,6 +62,7 @@ describe('aiSlashCommands', () => {
     expect(featured).toContain('/health');
     expect(featured).toContain('/mcp');
     expect(featured).toContain('/mcpadd');
+    expect(featured).toContain('/connfail');
     expect(featured).not.toContain('/shortcuts');
   });
 });
diff --git a/frontend/src/components/ai/aiSlashCommands.ts b/frontend/src/components/ai/aiSlashCommands.ts
index 44fce4c..21a4e2b 100644
--- a/frontend/src/components/ai/aiSlashCommands.ts
+++ b/frontend/src/components/ai/aiSlashCommands.ts
@@ -50,6 +50,7 @@ export const DEFAULT_AI_SLASH_COMMANDS: AISlashCommandDefinition[] = [
   { cmd: '/health', label: '🩺 AI 配置体检', desc: '调用体检探针总览当前 AI 配置', prompt: '请先调用 inspect_ai_setup_health，对当前 GoNavi AI 配置做一次完整体检，然后总结 blockers、warnings 和 nextActions。', category: 'diagnose', featured: true, keywords: ['health', '体检', 'ai配置', '探针'] },
   { cmd: '/mcp', label: '🪛 排查 MCP 接入', desc: '检查 MCP 服务和外部客户端状态', prompt: '请先调用 inspect_mcp_setup，帮我盘点当前 MCP 服务、工具发现结果，以及 Claude Code / Codex 的接入状态。', category: 'diagnose', featured: true, keywords: ['mcp', 'codex', 'claude', '外部客户端'] },
   { cmd: '/mcpadd', label: '🧭 新增 MCP 指引', desc: '查看 command、args、env 和模板怎么填', prompt: '请先调用 inspect_mcp_authoring_guide，再结合 inspect_mcp_setup，告诉我新增 GoNavi MCP 服务时 command、args、env、timeout 应该怎么填，以及最接近的模板应该选哪个。', category: 'diagnose', featured: true, keywords: ['mcp新增', 'command', 'args', 'env', '模板'] },
+  { cmd: '/connfail', label: '🧯 连接失败探针', desc: '总结最近连接失败、冷却和验证异常', prompt: '请先调用 inspect_recent_connection_failures，帮我总结最近数据库连接失败、连接冷却、验证失败和 SSH 隧道异常的真实日志结论；如果已经有明确地址或类型，再结合 inspect_current_connection 或 inspect_saved_connections 继续缩小范围。', category: 'diagnose', featured: true, keywords: ['连接失败', '冷却', '验证失败', 'ssh', 'mysql'] },
   { cmd: '/shortcuts', label: '⌨️ 快捷键探针', desc: '读取当前 Win/Mac 快捷键配置', prompt: '请先调用 inspect_shortcuts，告诉我当前 GoNavi 的快捷键配置，尤其是执行 SQL、切换结果区、打开 AI 面板和 AI 发送消息这些动作在当前平台和另一平台分别怎么按，是否改过默认值。', category: 'diagnose', keywords: ['快捷键', 'shortcuts', '结果区', 'mac', 'windows'] },
   { cmd: '/applog', label: '🪵 应用日志', desc: '回看最近 GoNavi 应用日志', prompt: '请先调用 inspect_app_logs，帮我看最近 GoNavi 应用日志里的错误和警告；如果我提到连接失败、MCP 拉起失败、启动异常或 gonavi.log，就优先结合关键词继续筛。', category: 'diagnose', keywords: ['日志', 'gonavi.log', 'mcp报错', '连接失败', '启动异常'] },
   { cmd: '/airender', label: '🧯 AI 渲染异常', desc: '读取最近一次 AI 消息渲染失败记录', prompt: '请先调用 inspect_ai_last_render_error，告诉我最近一次 AI 消息渲染失败记录里是哪条消息、报错摘要是什么，以及下一步该怎么排查。', category: 'diagnose', keywords: ['渲染失败', '气泡空白', 'ai消息', 'render', '白块'] },
diff --git a/frontend/src/components/ai/aiSnapshotInspectionToolExecutor.ts b/frontend/src/components/ai/aiSnapshotInspectionToolExecutor.ts
index b1f7817..eb5d63a 100644
--- a/frontend/src/components/ai/aiSnapshotInspectionToolExecutor.ts
+++ b/frontend/src/components/ai/aiSnapshotInspectionToolExecutor.ts
@@ -34,6 +34,7 @@ import {
 } from './aiWorkspaceInsights';
 import { buildShortcutSnapshot } from './aiShortcutInsights';
 import { buildAILastRenderErrorSnapshot } from './aiLastRenderErrorInsights';
+import { buildRecentConnectionFailureSnapshot } from './aiConnectionFailureInsights';
 import { executeAIConfigSnapshotToolCall } from './aiSnapshotInspectionAIConfigToolExecutor';
 import type {
   AISnapshotInspectionRuntime,
@@ -269,6 +270,25 @@ export async function executeSnapshotInspectionToolCall(
           success: true,
         };
       }
+      case 'inspect_recent_connection_failures': {
+        const readResult = typeof runtime?.readAppLogTail === 'function'
+          ? await runtime.readAppLogTail(Number(args.lineLimit) || 120, String(args.keyword || ''))
+          : { success: false, message: '当前环境暂不支持读取 GoNavi 应用日志' };
+        if (!readResult?.success) {
+          return {
+            content: `读取最近连接失败记录失败: ${readResult?.message || '未知错误'}`,
+            success: false,
+          };
+        }
+        return {
+          content: JSON.stringify(buildRecentConnectionFailureSnapshot({
+            readResult,
+            keyword: args.keyword,
+            lineLimit: args.lineLimit,
+          })),
+          success: true,
+        };
+      }
       case 'inspect_ai_last_render_error':
         return {
           content: JSON.stringify(buildAILastRenderErrorSnapshot()),
@@ -335,6 +355,7 @@ export async function executeSnapshotInspectionToolCall(
       inspect_recent_sql_logs: '获取最近 SQL 日志失败',
       inspect_recent_sql_activity: '汇总最近 SQL 活动失败',
       inspect_app_logs: '读取 GoNavi 应用日志失败',
+      inspect_recent_connection_failures: '汇总最近连接失败记录失败',
       inspect_ai_last_render_error: '读取最近一次 AI 渲染异常失败',
       inspect_saved_queries: '读取已保存查询失败',
       inspect_sql_snippets: '读取 SQL 片段失败',
diff --git a/frontend/src/components/ai/aiSystemContextMessages.test.ts b/frontend/src/components/ai/aiSystemContextMessages.test.ts
index 6f06ecd..5f921e1 100644
--- a/frontend/src/components/ai/aiSystemContextMessages.test.ts
+++ b/frontend/src/components/ai/aiSystemContextMessages.test.ts
@@ -68,7 +68,7 @@ describe('buildAISystemContextMessages', () => {
       connections: [connections[0]],
       tabs: [],
       activeTabId: null,
-      availableToolNames: ['inspect_workspace_tabs', 'inspect_ai_setup_health', 'inspect_ai_runtime', 'inspect_ai_safety', 'inspect_ai_providers', 'inspect_ai_chat_readiness', 'inspect_mcp_setup', 'inspect_mcp_authoring_guide', 'inspect_ai_guidance', 'inspect_ai_context', 'inspect_current_connection', 'inspect_connection_capabilities', 'inspect_saved_connections', 'inspect_external_sql_directories', 'inspect_external_sql_file', 'inspect_recent_sql_activity', 'inspect_app_logs', 'inspect_ai_last_render_error', 'inspect_saved_queries', 'inspect_ai_sessions', 'inspect_sql_snippets', 'inspect_shortcuts', 'get_columns'],
+      availableToolNames: ['inspect_workspace_tabs', 'inspect_ai_setup_health', 'inspect_ai_runtime', 'inspect_ai_safety', 'inspect_ai_providers', 'inspect_ai_chat_readiness', 'inspect_mcp_setup', 'inspect_mcp_authoring_guide', 'inspect_ai_guidance', 'inspect_ai_context', 'inspect_current_connection', 'inspect_connection_capabilities', 'inspect_saved_connections', 'inspect_external_sql_directories', 'inspect_external_sql_file', 'inspect_recent_sql_activity', 'inspect_recent_connection_failures', 'inspect_app_logs', 'inspect_ai_last_render_error', 'inspect_saved_queries', 'inspect_ai_sessions', 'inspect_sql_snippets', 'inspect_shortcuts', 'get_columns'],
       skills,
       userPromptSettings,
     });
@@ -90,6 +90,7 @@ describe('buildAISystemContextMessages', () => {
     expect(joined).toContain('inspect_external_sql_directories');
     expect(joined).toContain('inspect_external_sql_file');
     expect(joined).toContain('inspect_recent_sql_activity');
+    expect(joined).toContain('inspect_recent_connection_failures 读取真实连接失败总结');
     expect(joined).toContain('inspect_app_logs 读取真实应用日志尾部');
     expect(joined).toContain('inspect_ai_last_render_error 读取最近一次被隔离的前端渲染异常记录');
     expect(joined).toContain('inspect_saved_queries');
diff --git a/frontend/src/components/ai/aiSystemContextMessages.ts b/frontend/src/components/ai/aiSystemContextMessages.ts
index 0056641..49d5e47 100644
--- a/frontend/src/components/ai/aiSystemContextMessages.ts
+++ b/frontend/src/components/ai/aiSystemContextMessages.ts
@@ -225,6 +225,19 @@ const appendAppLogInspectionGuidance = (
   });
 };
 
+const appendConnectionFailureInspectionGuidance = (
+  messages: AISystemContextMessage[],
+  availableToolNames: string[],
+) => {
+  if (!availableToolNames.includes('inspect_recent_connection_failures')) {
+    return;
+  }
+  messages.push({
+    role: 'system',
+    content: '如果用户提到“为什么连接不上”“连接最近失败，正在冷却中”“验证失败”“SSH 隧道是不是有问题”“multiStatements / 参数兼容异常”，优先调用 inspect_recent_connection_failures 读取真实连接失败总结，再决定是否继续下钻 inspect_current_connection、inspect_saved_connections 或 inspect_app_logs。',
+  });
+};
+
 const appendAILastRenderErrorInspectionGuidance = (
   messages: AISystemContextMessage[],
   availableToolNames: string[],
@@ -478,6 +491,7 @@ SELECT * FROM users WHERE status = 1;
   appendMCPAuthoringInspectionGuidance(systemMessages, availableToolNames);
   appendAIGuidanceInspectionGuidance(systemMessages, availableToolNames);
   appendShortcutInspectionGuidance(systemMessages, availableToolNames);
+  appendConnectionFailureInspectionGuidance(systemMessages, availableToolNames);
   appendAppLogInspectionGuidance(systemMessages, availableToolNames);
   appendAILastRenderErrorInspectionGuidance(systemMessages, availableToolNames);
   if (availableToolNames.includes('inspect_current_connection')) {
diff --git a/frontend/src/components/ai/messageBubble/AIMessageStatusBlocks.tsx b/frontend/src/components/ai/messageBubble/AIMessageStatusBlocks.tsx
index 111bc77..5999111 100644
--- a/frontend/src/components/ai/messageBubble/AIMessageStatusBlocks.tsx
+++ b/frontend/src/components/ai/messageBubble/AIMessageStatusBlocks.tsx
@@ -52,6 +52,7 @@ const TOOL_ACTION_LABELS: Record<string, string> = {
   inspect_recent_sql_logs: '回看最近 SQL 执行日志',
   inspect_recent_sql_activity: '总结最近 SQL 活动',
   inspect_app_logs: '回看 GoNavi 应用日志',
+  inspect_recent_connection_failures: '总结最近连接失败记录',
   inspect_ai_last_render_error: '读取最近一次 AI 渲染异常',
   inspect_saved_queries: '检索本地已保存查询',
   inspect_sql_snippets: '读取 SQL 片段模板',
diff --git a/frontend/src/utils/aiBuiltinInspectionToolInfo.ts b/frontend/src/utils/aiBuiltinInspectionToolInfo.ts
index 2d41f02..49ed779 100644
--- a/frontend/src/utils/aiBuiltinInspectionToolInfo.ts
+++ b/frontend/src/utils/aiBuiltinInspectionToolInfo.ts
@@ -401,6 +401,29 @@ export const BUILTIN_AI_INSPECTION_TOOL_INFO: AIBuiltinToolInfo[] = [
       },
     },
   },
+  {
+    name: "inspect_recent_connection_failures",
+    icon: "🧯",
+    desc: "总结最近数据库连接失败与冷却原因",
+    detail:
+      "从最近一段 gonavi.log 里提取数据库连接失败、连接验证失败、SSH 隧道异常和连接冷却命中记录，自动归类主要问题类型、最新地址、最新根因和下一步建议。适合用户提到“为什么连接不上”“连接最近失败正在冷却”“验证失败”“SSH 隧道是不是有问题”时，先读这份结构化总结，而不是人工翻整段日志。",
+    params: "keyword?, lineLimit?(默认 120)",
+    tool: {
+      type: "function",
+      function: {
+        name: "inspect_recent_connection_failures",
+        description:
+          "汇总最近 GoNavi 应用日志中的数据库连接失败、连接验证失败、SSH 隧道失败和冷却命中记录，并返回主要异常类别、最新地址、最新根因与建议动作。适用于用户提到为什么连接不上、最近一直命中连接冷却、服务端验证失败、multiStatements 或参数兼容异常时，优先读取这份结构化连接失败总结，不要直接让模型肉眼翻整段日志。",
+        parameters: {
+          type: "object",
+          properties: {
+            keyword: { type: "string", description: "可选，按连接类型、地址或异常关键词过滤，例如 mysql、ssh、timeout、127.0.0.1" },
+            lineLimit: { type: "number", description: "可选，最多分析多少行日志，默认 120，最大 240" },
+          },
+        },
+      },
+    },
+  },
   {
     name: "inspect_ai_last_render_error",
     icon: "🧯",
diff --git a/frontend/src/utils/aiToolRegistry.test.ts b/frontend/src/utils/aiToolRegistry.test.ts
index 933ebf4..d544fc2 100644
--- a/frontend/src/utils/aiToolRegistry.test.ts
+++ b/frontend/src/utils/aiToolRegistry.test.ts
@@ -108,6 +108,13 @@ describe('aiToolRegistry', () => {
     expect(info?.tool.function.description).toContain('gonavi.log');
   });
 
+  it('registers the recent-connection-failure inspector as a builtin tool', () => {
+    const info = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_recent_connection_failures');
+    expect(info).toBeTruthy();
+    expect(info?.desc).toContain('连接失败');
+    expect(info?.tool.function.description).toContain('multiStatements');
+  });
+
   it('registers the ai-render-error inspector as a builtin tool', () => {
     const info = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_ai_last_render_error');
     expect(info).toBeTruthy();
@@ -118,6 +125,7 @@ describe('aiToolRegistry', () => {
   it('registers the recent-sql-activity, saved-query, and sql-snippet inspectors as builtin tools', () => {
     const recentActivityTool = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_recent_sql_activity');
     const appLogTool = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_app_logs');
+    const connectionFailureTool = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_recent_connection_failures');
     const renderErrorTool = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_ai_last_render_error');
     const savedQueryTool = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_saved_queries');
     const aiSessionsTool = BUILTIN_AI_TOOL_INFO.find((item) => item.name === 'inspect_ai_sessions');
@@ -127,6 +135,8 @@ describe('aiToolRegistry', () => {
     expect(recentActivityTool?.tool.function.description).toContain('最近 SQL 活动');
     expect(appLogTool?.desc).toContain('GoNavi 应用日志');
     expect(appLogTool?.tool.function.description).toContain('应用日志');
+    expect(connectionFailureTool?.desc).toContain('连接失败');
+    expect(connectionFailureTool?.tool.function.description).toContain('连接冷却');
     expect(renderErrorTool?.desc).toContain('渲染异常记录');
     expect(renderErrorTool?.tool.function.description).toContain('气泡局部报错');
     expect(savedQueryTool?.desc).toContain('已保存的 SQL 查询');
@@ -168,6 +178,7 @@ describe('aiToolRegistry', () => {
     expect(tools.some((item) => item.function.name === 'inspect_external_sql_file')).toBe(true);
     expect(tools.some((item) => item.function.name === 'inspect_recent_sql_activity')).toBe(true);
     expect(tools.some((item) => item.function.name === 'inspect_app_logs')).toBe(true);
+    expect(tools.some((item) => item.function.name === 'inspect_recent_connection_failures')).toBe(true);
     expect(tools.some((item) => item.function.name === 'inspect_ai_last_render_error')).toBe(true);
     expect(tools.some((item) => item.function.name === 'inspect_saved_queries')).toBe(true);
     expect(tools.some((item) => item.function.name === 'inspect_ai_sessions')).toBe(true);