Python: [Python]: A2A server omits function_call and function_result content

[moonbox3]

Discussed in #6940

^{Originally posted by wigging July 7, 2026}
I have an agent that uses an MCP server for one of its tools as demonstrated below.

agent = Agent(
    client,
    instructions,
    name="My Agent",
    description="Agent for the system",
    tools=[my_mcp],
)

This agent is served with the A2A protocol as shown next.

agent_card = AgentCard(
    name="My Agent",
    description="Agent for the system",
)

request_handler = DefaultRequestHandler(
    agent_executor=A2AExecutor(agent),
    task_store=InMemoryTaskStore(),
    agent_card=agent_card,
)

app = Starlette(
    routes=[
        *create_agent_card_routes(agent_card),
        *create_jsonrpc_routes(request_handler, "/"),
    ]
)

uvicorn.run(app)

To test this agent I have some client code as shown below. This connects to the remote A2A agent which, for demo purposes, is running on localhost port 8000.

# client.py

a2a_url = "http://127.0.0.1:8000"
agent = A2AAgent(name="My A2A Agent", url=a2a_url)

user_prompt = "what is status of the system"
print(f"\nUser Prompt:\n{user_prompt}")

response = await agent.run(user_prompt)
print(f"\nRemote Agent Response:\n\033[96m{response}\033[0m")

Everything works fine but I noticed the A2A server gives the following output when the client sends a request:

A2AExecutor does not yet support content type: function_call. Omitted.
A2AExecutor does not yet support content type: function_result. Omitted.

I think this is caused by the MCP tool on the remote agent. Is this something I need to worry about or should I just ignore it? Is there a way to prevent these A2AExecutor log statements from displaying in the server output?

[wigging]

I don't know if this is related to the issue, but in the example code that I provided above, I'm only using the URL to create the agent. I'm not fetching the agent card that provides more details about the remote agent.

agent = A2AAgent(name="My A2A Agent", url=a2a_url)

[giles17]

Hey @wigging thanks for the report! You can safely ignore these, nothing is broken. When your agent calls a tool (e.g. via MCP), its response messages contain intermediate function_call and function_result content parts. The A2A protocol only surfaces the final user-facing output (text/data/URI), so these intermediate parts are intentionally omitted, the final answer still reaches your client correctly.

[wigging]

Ok, thanks for the response. Hopefully the pull request will silence the output.