diff --git a/app/agent/__init__.py b/app/agent/__init__.py
index dd44e3e6d..d797a3f2d 100644
--- a/app/agent/__init__.py
+++ b/app/agent/__init__.py
@@ -722,6 +722,9 @@ class MoviePilotAgent:
             "reply_mode": None,
             "should_dispatch_reply": should_dispatch_reply,
             "is_admin": await self._is_system_admin_context(),
+            # 工具回调消息需要发回原会话（群聊@机器人时按钮选择等卡片不能发到私聊），
+            # 后台任务无渠道上下文时置空，交由通知链广播。
+            "original_chat_id": None if self.is_background else self.original_chat_id,
         }
 
     def _should_stream(self) -> bool:
diff --git a/app/agent/tools/base.py b/app/agent/tools/base.py
index 0adbde982..bed361aed 100644
--- a/app/agent/tools/base.py
+++ b/app/agent/tools/base.py
@@ -658,6 +658,16 @@ class MoviePilotTool(BaseTool, metaclass=ABCMeta):
                     "original_chat_id": None,
                 }
             )
+        elif not notification.original_chat_id:
+            # 工具回调消息默认回填当前会话的原会话 ID，
+            # 保证群聊 @ 机器人时按钮选择、消息发送等交互消息回复到原群，而不是私聊窗口。
+            original_chat_id = str(
+                self._agent_context.get("original_chat_id") or ""
+            ).strip() or None
+            if original_chat_id:
+                notification = notification.model_copy(
+                    update={"original_chat_id": original_chat_id}
+                )
 
         await ToolChain().async_post_message(notification)
 
diff --git a/tests/test_agent_tool_message_target.py b/tests/test_agent_tool_message_target.py
new file mode 100644
index 000000000..114e2eb66
--- /dev/null
+++ b/tests/test_agent_tool_message_target.py
@@ -0,0 +1,127 @@
+"""Agent 工具回调消息回复目标（original_chat_id 回填）的测试。"""
+
+import asyncio
+from unittest.mock import AsyncMock, patch
+
+from app.agent.tools.impl.ask_user_choice import (
+    AskUserChoiceTool,
+    UserChoiceOptionInput,
+)
+from app.agent.tools.impl.send_message import SendMessageTool
+from app.schemas import Notification
+from app.schemas.types import MessageChannel
+
+
+def _run_choice_tool(agent_context: dict, channel: str, source: str) -> Notification:
+    """运行按钮选择工具并返回其发送的通知。"""
+    tool = AskUserChoiceTool(session_id="session-1", user_id="ou_xxx")
+    tool.set_message_attr(
+        channel=channel,
+        source=source,
+        username="tester",
+    )
+    tool.set_agent_context(agent_context=agent_context)
+
+    with patch(
+        "app.agent.tools.base.ToolChain.async_post_message",
+        new=AsyncMock(),
+    ) as async_post_message:
+        asyncio.run(
+            tool.run(
+                message="请选择",
+                options=[UserChoiceOptionInput(label="继续", value="继续")],
+            )
+        )
+
+    assert async_post_message.await_count == 1
+    return async_post_message.await_args.args[0]
+
+
+def test_choice_tool_backfills_original_chat_id_from_session_context():
+    """群聊场景下按钮选择通知应回填会话上下文中的 original_chat_id。"""
+    notification = _run_choice_tool(
+        agent_context={"original_chat_id": "oc_group_123"},
+        channel=MessageChannel.Feishu.value,
+        source="feishu-test",
+    )
+
+    assert notification.original_chat_id == "oc_group_123"
+    assert notification.userid == "ou_xxx"
+
+
+def test_choice_tool_keeps_explicit_original_chat_id():
+    """按钮选择通知已显式携带原会话 ID 时不应被上下文覆盖。"""
+    notification = _run_choice_tool(
+        agent_context={"original_chat_id": "oc_group_zzz"},
+        channel=MessageChannel.Telegram.value,
+        source="telegram-test",
+    )
+
+    assert notification.original_chat_id == "oc_group_zzz"
+
+
+def test_choice_tool_no_context_does_not_backfill():
+    """会话上下文未携带原会话 ID 时，通知保持原有发送目标。"""
+    notification = _run_choice_tool(
+        agent_context={},
+        channel=MessageChannel.Telegram.value,
+        source="telegram-test",
+    )
+
+    assert notification.original_chat_id is None
+
+
+def test_background_tool_clears_original_chat_id():
+    """无渠道上下文的后台任务应清空渠道定位信息交由消息链广播。"""
+    tool = SendMessageTool(session_id="session-1", user_id="ou_xxx")
+    tool.set_agent_context(agent_context={"original_chat_id": "oc_group_123"})
+
+    with patch(
+        "app.agent.tools.base.ToolChain.async_post_message",
+        new=AsyncMock(),
+    ) as async_post_message:
+        asyncio.run(tool.send_tool_message("后台任务执行完成"))
+
+    notification = async_post_message.await_args.args[0]
+    assert notification.original_chat_id is None
+    assert notification.channel is None
+    assert notification.userid is None
+
+
+def test_send_tool_message_backfills_original_chat_id():
+    """send_tool_message 工具消息同样应回填原会话 ID。"""
+    tool = SendMessageTool(session_id="session-1", user_id="ou_xxx")
+    tool.set_message_attr(
+        channel=MessageChannel.Feishu.value,
+        source="feishu-test",
+        username="tester",
+    )
+    tool.set_agent_context(agent_context={"original_chat_id": "oc_group_123"})
+
+    with patch(
+        "app.agent.tools.base.ToolChain.async_post_message",
+        new=AsyncMock(),
+    ) as async_post_message:
+        asyncio.run(tool.send_tool_message("正在执行操作"))
+
+    notification = async_post_message.await_args.args[0]
+    assert notification.original_chat_id == "oc_group_123"
+
+
+def test_tool_context_includes_original_chat_id():
+    """工具共享上下文应携带当前会话的原会话 ID。"""
+    from app.agent import MoviePilotAgent
+
+    agent = MoviePilotAgent(
+        session_id="session-1",
+        user_id="ou_xxx",
+        channel=MessageChannel.Feishu.value,
+        source="feishu-test",
+        username="tester",
+        original_chat_id="oc_group_123",
+    )
+
+    with patch.object(MoviePilotAgent, "_is_system_admin_context", return_value=False):
+        context = asyncio.run(agent._build_tool_context(should_dispatch_reply=True))
+
+    assert context["original_chat_id"] == "oc_group_123"
\ No newline at end of file