diff --git a/app/agent/tools/impl/send_message.py b/app/agent/tools/impl/send_message.py
index 998ebe57..028412e9 100644
--- a/app/agent/tools/impl/send_message.py
+++ b/app/agent/tools/impl/send_message.py
@@ -1,5 +1,7 @@
 """发送消息工具"""
 
+import html as html_utils
+import re
 from typing import Optional, Type
 
 from pydantic import BaseModel, Field, model_validator
@@ -17,6 +19,41 @@ SEND_MESSAGE_PARSE_MODE_ALIASES = {
     "mdv2": SEND_MESSAGE_PARSE_MODE_MARKDOWN,
     "html": SEND_MESSAGE_PARSE_MODE_HTML,
 }
+SEND_MESSAGE_HTML_ALLOWED_TAGS = {
+    "a",
+    "b",
+    "blockquote",
+    "code",
+    "del",
+    "em",
+    "i",
+    "ins",
+    "pre",
+    "s",
+    "span",
+    "strike",
+    "strong",
+    "tg-spoiler",
+    "u",
+}
+SEND_MESSAGE_HTML_NORMALIZATION_RULES = (
+    (re.compile(r"<\s*br\s*/?\s*>", re.IGNORECASE), "\n"),
+    (re.compile(r"<\s*/\s*p\s*>", re.IGNORECASE), "\n"),
+    (re.compile(r"<\s*p(?:\s+[^>]*)?>", re.IGNORECASE), ""),
+    (re.compile(r"<\s*/\s*div\s*>", re.IGNORECASE), "\n"),
+    (re.compile(r"<\s*div(?:\s+[^>]*)?>", re.IGNORECASE), ""),
+    (re.compile(r"<\s*/\s*li\s*>", re.IGNORECASE), "\n"),
+    (re.compile(r"<\s*li(?:\s+[^>]*)?>", re.IGNORECASE), "• "),
+    (re.compile(r"<\s*/?\s*(?:ul|ol)(?:\s+[^>]*)?>", re.IGNORECASE), ""),
+    (re.compile(r"<\s*h[1-6](?:\s+[^>]*)?>", re.IGNORECASE), "<b>"),
+    (re.compile(r"<\s*/\s*h[1-6]\s*>", re.IGNORECASE), "</b>\n"),
+)
+SEND_MESSAGE_HTML_TAG_PATTERN = re.compile(
+    r"<\s*(/?)\s*([a-zA-Z][\w:-]*)\b([^>]*)>"
+)
+SEND_MESSAGE_HTML_ATTR_PATTERN_TEMPLATE = (
+    r"""\b{attr_name}\s*=\s*(?:"([^"]*)"|'([^']*)'|([^\s"'>]+))"""
+)
 
 
 class SendMessageInput(BaseModel):
@@ -52,6 +89,8 @@ class SendMessageInput(BaseModel):
         if not self.message and not self.title and not self.image_url:
             raise ValueError("message、title、image_url 至少需要提供一个")
         self.parse_mode = SendMessageTool.normalize_parse_mode(self.parse_mode)
+        if self.parse_mode == SEND_MESSAGE_PARSE_MODE_HTML:
+            self.message = SendMessageTool.normalize_html_message(self.message)
         return self
 
 
@@ -63,13 +102,17 @@ class SendMessageTool(MoviePilotTool):
         ToolTag.Write,
         ToolTag.Message,
         ToolTag.Admin,
+        ToolTag.TerminalResponse,
     ]
     sends_message: bool = True
+    return_direct: bool = True
     description: str = (
         "Send notification message to the user through configured notification channels "
         "(Telegram, Slack, WeChat, etc.). Supports optional image_url on channels that can "
         "send images. For Telegram, the optional parse_mode parameter controls message body "
-        "rendering. Supported values are HTML and MarkdownV2; leave it empty for default."
+        "rendering. Supported values are HTML and MarkdownV2; leave it empty for default. "
+        "This is a terminal response tool: after it sends the user-facing message, do not "
+        "send another final text reply with the same content."
     )
     args_schema: Type[BaseModel] = SendMessageInput
     require_admin: bool = True
@@ -86,6 +129,72 @@ class SendMessageTool(MoviePilotTool):
             raise ValueError("parse_mode 仅支持 MarkdownV2 或 HTML")
         return normalized
 
+    @staticmethod
+    def _extract_html_attr(attrs: str, attr_name: str) -> Optional[str]:
+        """
+        从 HTML 标签属性中提取指定属性值。
+        """
+        pattern = SEND_MESSAGE_HTML_ATTR_PATTERN_TEMPLATE.format(
+            attr_name=re.escape(attr_name)
+        )
+        match = re.search(pattern, attrs or "", re.IGNORECASE)
+        if not match:
+            return None
+        return next((value for value in match.groups() if value is not None), None)
+
+    @staticmethod
+    def _normalize_html_tag(match: re.Match) -> str:
+        """
+        规范化 Telegram 支持的 HTML 标签，并剥离不支持的属性。
+        """
+        closing, tag_name, attrs = match.groups()
+        tag_name = tag_name.lower()
+        if tag_name not in SEND_MESSAGE_HTML_ALLOWED_TAGS:
+            raise ValueError(f"HTML 标签 <{tag_name}> 不受 Telegram 支持")
+
+        if closing:
+            return f"</{tag_name}>"
+
+        if tag_name == "a":
+            href = SendMessageTool._extract_html_attr(attrs, "href")
+            if not href:
+                raise ValueError("HTML 标签 <a> 必须包含 href 属性")
+            return f'<a href="{html_utils.escape(href, quote=True)}">'
+
+        if tag_name == "span":
+            class_name = SendMessageTool._extract_html_attr(attrs, "class")
+            if class_name != "tg-spoiler":
+                raise ValueError('HTML 标签 <span> 仅支持 class="tg-spoiler"')
+            return '<span class="tg-spoiler">'
+
+        if tag_name == "blockquote":
+            if re.search(r"(^|\s)expandable(\s|/|$)", attrs or "", re.IGNORECASE):
+                return "<blockquote expandable>"
+            return "<blockquote>"
+
+        if tag_name == "code":
+            class_name = SendMessageTool._extract_html_attr(attrs, "class")
+            if class_name and class_name.startswith("language-"):
+                escaped_class = html_utils.escape(class_name, quote=True)
+                return f'<code class="{escaped_class}">'
+            return "<code>"
+
+        return f"<{tag_name}>"
+
+    @staticmethod
+    def normalize_html_message(message: Optional[str]) -> Optional[str]:
+        """
+        规范化 Agent 生成的 Telegram HTML 正文。
+        """
+        if not message:
+            return message
+        normalized = message
+        for pattern, replacement in SEND_MESSAGE_HTML_NORMALIZATION_RULES:
+            normalized = pattern.sub(replacement, normalized)
+        return SEND_MESSAGE_HTML_TAG_PATTERN.sub(
+            SendMessageTool._normalize_html_tag, normalized
+        )
+
     def get_tool_message(self, **kwargs) -> Optional[str]:
         """根据消息参数生成友好的提示消息"""
         message = kwargs.get("message", "") or ""
@@ -117,6 +226,8 @@ class SendMessageTool(MoviePilotTool):
         text = message or ""
         try:
             parse_mode = self.normalize_parse_mode(parse_mode)
+            if parse_mode == SEND_MESSAGE_PARSE_MODE_HTML:
+                text = self.normalize_html_message(text) or ""
         except ValueError as e:
             return str(e)
 
@@ -138,6 +249,8 @@ class SendMessageTool(MoviePilotTool):
                     parse_mode=parse_mode,
                 )
             )
+            self._agent_context["user_reply_sent"] = True
+            self._agent_context["reply_mode"] = "send_message"
             return "消息已发送"
         except Exception as e:
             logger.error(f"发送消息失败: {e}")
diff --git a/tests/test_agent_image_support.py b/tests/test_agent_image_support.py
index faf581e3..2be0a19e 100644
--- a/tests/test_agent_image_support.py
+++ b/tests/test_agent_image_support.py
@@ -578,6 +578,28 @@ class AgentImageSupportTest(unittest.TestCase):
 
         self.assertEqual(payload.parse_mode, "HTML")
 
+    def test_send_message_input_normalizes_common_html_tags(self):
+        payload = SendMessageInput(
+            explanation="send html notice",
+            message="<h1>标题</h1><p>第一行<br>第二行</p><ul><li>A</li></ul>",
+            parse_mode="HTML",
+        )
+
+        self.assertEqual(
+            payload.message,
+            "<b>标题</b>\n第一行\n第二行\n• A\n",
+        )
+
+    def test_send_message_input_rejects_unsupported_html_tags(self):
+        with self.assertRaises(ValueError) as error:
+            SendMessageInput(
+                explanation="send html notice",
+                message="<table><tr><td>A</td></tr></table>",
+                parse_mode="HTML",
+            )
+
+        self.assertIn("HTML 标签 <table> 不受 Telegram 支持", str(error.exception))
+
     def test_send_message_tool_uses_regular_notification_type(self):
         """发送消息工具应按普通通知消息登记。"""
 
@@ -613,6 +635,58 @@ class AgentImageSupportTest(unittest.TestCase):
         self.assertEqual(notification.image, "https://example.com/poster.png")
         self.assertEqual(notification.parse_mode, "HTML")
 
+    def test_send_message_tool_marks_reply_sent_after_dispatch(self):
+        """发送消息工具成功发送后应终止本轮回复。"""
+
+        async def _run():
+            tool = SendMessageTool(session_id="session-1", user_id="10001")
+            agent_context = {}
+            tool.set_agent_context(agent_context)
+            tool.set_message_attr(
+                channel=MessageChannel.Telegram.value,
+                source="telegram-test",
+                username="tester",
+            )
+
+            with patch(
+                "app.agent.tools.base.ToolChain.async_post_message",
+                new_callable=AsyncMock,
+            ):
+                result = await tool.run(message="<b>处理完成</b>", parse_mode="HTML")
+            return result, agent_context
+
+        result, agent_context = asyncio.run(_run())
+
+        self.assertEqual(result, "消息已发送")
+        self.assertTrue(agent_context["user_reply_sent"])
+        self.assertEqual(agent_context["reply_mode"], "send_message")
+
+    def test_send_message_tool_rejects_unsupported_html_before_dispatch(self):
+        """发送消息工具应在进入消息链路前拒绝不支持的 HTML。"""
+
+        async def _run():
+            tool = SendMessageTool(session_id="session-1", user_id="10001")
+            tool.set_message_attr(
+                channel=MessageChannel.Telegram.value,
+                source="telegram-test",
+                username="tester",
+            )
+
+            with patch(
+                "app.agent.tools.base.ToolChain.async_post_message",
+                new_callable=AsyncMock,
+            ) as async_post_message:
+                result = await tool.run(
+                    message="<table><tr><td>A</td></tr></table>",
+                    parse_mode="HTML",
+                )
+            return result, async_post_message
+
+        result, async_post_message = asyncio.run(_run())
+
+        self.assertIn("HTML 标签 <table> 不受 Telegram 支持", result)
+        async_post_message.assert_not_awaited()
+
     def test_send_message_tool_rejects_invalid_parse_mode(self):
         """发送消息工具应拒绝不支持的格式类型。"""
 
diff --git a/tests/test_agent_interaction.py b/tests/test_agent_interaction.py
index f47f3f70..838d14e2 100644
--- a/tests/test_agent_interaction.py
+++ b/tests/test_agent_interaction.py
@@ -8,6 +8,7 @@ from app.agent.tools.impl.ask_user_choice import (
     AskUserChoiceTool,
     UserChoiceOptionInput,
 )
+from app.agent.tools.impl.send_message import SendMessageTool
 from app.helper.interaction import (
     AgentInteractionOption,
     agent_interaction_manager,
@@ -89,6 +90,13 @@ class TestAgentInteraction(unittest.TestCase):
         self.assertTrue(tool.return_direct)
         self.assertIn("terminal interaction tool", tool.description)
 
+    def test_send_message_tool_returns_direct_after_sending_message(self):
+        """发送消息工具发出用户可见消息后应结束当前 Agent 轮次。"""
+        tool = SendMessageTool(session_id="session-1", user_id="10001")
+
+        self.assertTrue(tool.return_direct)
+        self.assertIn("terminal response tool", tool.description)
+
     def test_choice_tool_sends_buttons_and_registers_pending_request(self):
         tool = AskUserChoiceTool(session_id="session-1", user_id="10001")
         tool.set_message_attr(