diff --git a/nanobot/agent/loop.py b/nanobot/agent/loop.py
index 3e513cb..6155f99 100644
--- a/nanobot/agent/loop.py
+++ b/nanobot/agent/loop.py
@@ -441,16 +441,14 @@ class AgentLoop:
         if final_content is None:
             final_content = "I've completed processing but have no response to give."
 
-        preview = final_content[:120] + "..." if len(final_content) > 120 else final_content
-        logger.info("Response to {}:{}: {}", msg.channel, msg.sender_id, preview)
-
         self._save_turn(session, all_msgs, 1 + len(history))
         self.sessions.save(session)
 
-        if message_tool := self.tools.get("message"):
-            if isinstance(message_tool, MessageTool) and message_tool._sent_in_turn:
-                return None
+        if (mt := self.tools.get("message")) and isinstance(mt, MessageTool) and mt._sent_in_turn:
+            return None
 
+        preview = final_content[:120] + "..." if len(final_content) > 120 else final_content
+        logger.info("Response to {}:{}: {}", msg.channel, msg.sender_id, preview)
         return OutboundMessage(
             channel=msg.channel, chat_id=msg.chat_id, content=final_content,
             metadata=msg.metadata or {},
diff --git a/nanobot/agent/tools/message.py b/nanobot/agent/tools/message.py
index 40e76e3..35e519a 100644
--- a/nanobot/agent/tools/message.py
+++ b/nanobot/agent/tools/message.py
@@ -101,7 +101,8 @@ class MessageTool(Tool):
 
         try:
             await self._send_callback(msg)
-            self._sent_in_turn = True
+            if channel == self._default_channel and chat_id == self._default_chat_id:
+                self._sent_in_turn = True
             media_info = f" with {len(media)} attachments" if media else ""
             return f"Message sent to {channel}:{chat_id}{media_info}"
         except Exception as e:
diff --git a/tests/test_message_tool_suppress.py b/tests/test_message_tool_suppress.py
new file mode 100644
index 0000000..26b8a16
--- /dev/null
+++ b/tests/test_message_tool_suppress.py
@@ -0,0 +1,103 @@
+"""Test message tool suppress logic for final replies."""
+
+from pathlib import Path
+from unittest.mock import AsyncMock, MagicMock
+
+import pytest
+
+from nanobot.agent.loop import AgentLoop
+from nanobot.agent.tools.message import MessageTool
+from nanobot.bus.events import InboundMessage, OutboundMessage
+from nanobot.bus.queue import MessageBus
+from nanobot.providers.base import LLMResponse, ToolCallRequest
+
+
+def _make_loop(tmp_path: Path) -> AgentLoop:
+    bus = MessageBus()
+    provider = MagicMock()
+    provider.get_default_model.return_value = "test-model"
+    return AgentLoop(bus=bus, provider=provider, workspace=tmp_path, model="test-model", memory_window=10)
+
+
+class TestMessageToolSuppressLogic:
+    """Final reply suppressed only when message tool sends to the same target."""
+
+    @pytest.mark.asyncio
+    async def test_suppress_when_sent_to_same_target(self, tmp_path: Path) -> None:
+        loop = _make_loop(tmp_path)
+        tool_call = ToolCallRequest(
+            id="call1", name="message",
+            arguments={"content": "Hello", "channel": "feishu", "chat_id": "chat123"},
+        )
+        calls = iter([
+            LLMResponse(content="", tool_calls=[tool_call]),
+            LLMResponse(content="Done", tool_calls=[]),
+        ])
+        loop.provider.chat = AsyncMock(side_effect=lambda *a, **kw: next(calls))
+        loop.tools.get_definitions = MagicMock(return_value=[])
+
+        sent: list[OutboundMessage] = []
+        mt = loop.tools.get("message")
+        if isinstance(mt, MessageTool):
+            mt.set_send_callback(AsyncMock(side_effect=lambda m: sent.append(m)))
+
+        msg = InboundMessage(channel="feishu", sender_id="user1", chat_id="chat123", content="Send")
+        result = await loop._process_message(msg)
+
+        assert len(sent) == 1
+        assert result is None  # suppressed
+
+    @pytest.mark.asyncio
+    async def test_not_suppress_when_sent_to_different_target(self, tmp_path: Path) -> None:
+        loop = _make_loop(tmp_path)
+        tool_call = ToolCallRequest(
+            id="call1", name="message",
+            arguments={"content": "Email content", "channel": "email", "chat_id": "user@example.com"},
+        )
+        calls = iter([
+            LLMResponse(content="", tool_calls=[tool_call]),
+            LLMResponse(content="I've sent the email.", tool_calls=[]),
+        ])
+        loop.provider.chat = AsyncMock(side_effect=lambda *a, **kw: next(calls))
+        loop.tools.get_definitions = MagicMock(return_value=[])
+
+        sent: list[OutboundMessage] = []
+        mt = loop.tools.get("message")
+        if isinstance(mt, MessageTool):
+            mt.set_send_callback(AsyncMock(side_effect=lambda m: sent.append(m)))
+
+        msg = InboundMessage(channel="feishu", sender_id="user1", chat_id="chat123", content="Send email")
+        result = await loop._process_message(msg)
+
+        assert len(sent) == 1
+        assert sent[0].channel == "email"
+        assert result is not None  # not suppressed
+        assert result.channel == "feishu"
+
+    @pytest.mark.asyncio
+    async def test_not_suppress_when_no_message_tool_used(self, tmp_path: Path) -> None:
+        loop = _make_loop(tmp_path)
+        loop.provider.chat = AsyncMock(return_value=LLMResponse(content="Hello!", tool_calls=[]))
+        loop.tools.get_definitions = MagicMock(return_value=[])
+
+        msg = InboundMessage(channel="feishu", sender_id="user1", chat_id="chat123", content="Hi")
+        result = await loop._process_message(msg)
+
+        assert result is not None
+        assert "Hello" in result.content
+
+
+class TestMessageToolTurnTracking:
+
+    def test_sent_in_turn_tracks_same_target(self) -> None:
+        tool = MessageTool()
+        tool.set_context("feishu", "chat1")
+        assert not tool._sent_in_turn
+        tool._sent_in_turn = True
+        assert tool._sent_in_turn
+
+    def test_start_turn_resets(self) -> None:
+        tool = MessageTool()
+        tool._sent_in_turn = True
+        tool.start_turn()
+        assert not tool._sent_in_turn