async def test_chat_large_prompt_detection(self, large_prompt):
        """Test that chat tool detects large prompts."""
        tool = ChatTool()
        result = await tool.execute({"prompt": large_prompt})

        assert len(result) == 1
        assert isinstance(result[0], TextContent)

        output = json.loads(result[0].text)
        assert output["status"] == "requires_file_prompt"
        assert f"{MCP_PROMPT_SIZE_LIMIT:,} characters" in output["content"]
        assert output["metadata"]["prompt_size"] == len(large_prompt)
        assert output["metadata"]["limit"] == MCP_PROMPT_SIZE_LIMIT
Test that chat tool detects large prompts.
tests/test_large_prompt_handling.py