[MCP][Utils] Add support for FastMCP processing

[Czhang0727]

Fixing issue #630

Problem:
In FastMCP, the structure did not have array data inside of result, instead, the result itself is the array itself. And the text field is used.

Add a type check, if we found it an array, simply merge all results with the content. Please find the fixed test project here: https://github.com/Czhang0727/object-rag

[github-actions]

This PR is stale because it has been open for 10 days with no activity.

[Czhang0727]

seems no one is reviewing this change, plz let me know if there is any updates

[rm-openai]

Sorry was out on vacation! Will take a closer look soon.

[rm-openai]

Not totally understanding the issue here. When would the return type not have content?

[Czhang0727]

In the current code, we are expecting

result = {
content: [content_object]
}

in fastMCP, I got a response like

result = [content_object]

[rm-openai]

@Czhang0727 The spec is pretty clear that the response must be result: { content: [...] } } (https://modelcontextprotocol.io/specification/2025-03-26/server/tools#calling-tools).

So is it possible your server is not compliant?

[Czhang0727]

hmm, in that case, fastMCP may have some issue, let me check the behavior and get back to the thread