fix(feishu): avoid breaking tool hint formatting and think stripping

tests/test_feishu_tool_hint_code_block.py

@@ -114,3 +114,25 @@ async def test_tool_hint_multiple_tools_in_one_message(mock_feishu_channel):
         # Each tool call should be on its own line
         expected_md = "**Tool Calls**\n\n```text\nweb_search(\"query\"),\nread_file(\"/path/to/file\")\n```"
         assert content["elements"][0]["content"] == expected_md
+
+
+@mark.asyncio
+async def test_tool_hint_keeps_commas_inside_arguments(mock_feishu_channel):
+    """Commas inside a single tool argument must not be split onto a new line."""
+    msg = OutboundMessage(
+        channel="feishu",
+        chat_id="oc_123456",
+        content='web_search("foo, bar"), read_file("/path/to/file")',
+        metadata={"_tool_hint": True}
+    )
+
+    with patch.object(mock_feishu_channel, '_send_message_sync') as mock_send:
+        await mock_feishu_channel.send(msg)
+
+        content = json.loads(mock_send.call_args[0][3])
+        expected_md = (
+            "**Tool Calls**\n\n```text\n"
+            "web_search(\"foo, bar\"),\n"
+            "read_file(\"/path/to/file\")\n```"
+        )
+        assert content["elements"][0]["content"] == expected_md