fix: normalize MCP object schemas without properties

tests/tools/test_mcp_tool.py

@@ -106,6 +106,18 @@ class TestSchemaConversion:
         assert schema["parameters"]["type"] == "object"
         assert schema["parameters"]["properties"] == {}
 
+    def test_object_schema_without_properties_gets_normalized(self):
+        from tools.mcp_tool import _convert_mcp_schema
+
+        mcp_tool = _make_mcp_tool(
+            name="ask",
+            description="Ask Crawl4AI",
+            input_schema={"type": "object"},
+        )
+        schema = _convert_mcp_schema("crawl4ai", mcp_tool)
+
+        assert schema["parameters"] == {"type": "object", "properties": {}}
+
     def test_tool_name_prefix_format(self):
         from tools.mcp_tool import _convert_mcp_schema
 
@@ -1893,6 +1905,33 @@ class TestSamplingCallbackText:
         messages = call_args.kwargs["messages"]
         assert messages[0] == {"role": "system", "content": "Be helpful"}
 
+    def test_server_tools_with_object_schema_are_normalized(self):
+        """Server-provided tools should gain empty properties for object schemas."""
+        fake_client = MagicMock()
+        fake_client.chat.completions.create.return_value = _make_llm_response()
+        server_tool = SimpleNamespace(
+            name="ask",
+            description="Ask Crawl4AI",
+            inputSchema={"type": "object"},
+        )
+
+        with patch(
+            "agent.auxiliary_client.call_llm",
+            return_value=fake_client.chat.completions.create.return_value,
+        ) as mock_call:
+            params = _make_sampling_params(tools=[server_tool])
+            asyncio.run(self.handler(None, params))
+
+        tools = mock_call.call_args.kwargs["tools"]
+        assert tools == [{
+            "type": "function",
+            "function": {
+                "name": "ask",
+                "description": "Ask Crawl4AI",
+                "parameters": {"type": "object", "properties": {}},
+            },
+        }]
+
     def test_length_stop_reason(self):
         """finish_reason='length' maps to stopReason='maxTokens'."""
         fake_client = MagicMock()