Different response types?

[vincentparrett]

Firstly thanks for sharing this, it was trivial to get an MCP server up and running with it.

One issue I have found so far, is that it only supports a string response type. When running external tools, it would be useful to return an object type, so for example I could return the exit code and the stdout captured from the tool. That would improve the usefulness of the tools - claude often forgets how to deal with the tool output - providing a structured way for it to detect and understand failures would help a lot.

[cmgeuze]

Good point! Please have a look at the feature/structured-output-support branch, is that what you're looking for?

[vincentparrett]

Kind of - but your solution required more manual work and it doesn't report the outputSchema. I had a go at making it work here - https://github.com/VSoftTechnologies/Delphi-MCP-Server/tree/f-structured-output

Not really tested it properly yet though.

[cmgeuze]

Thanks! Found two issues:

1. TJSONArray serialization: RTTI serializes TJSONArray metadata instead of actual array content
2. Response format: Content array is always created, even for structured output

I've implemented fixes in a new branch that detect TJSONValue types and clone them directly (fixes array serialization), and uses structuredContent for JSON objects, content array only for strings

Fixes are available here:
https://github.com/GDKsoftware/Delphi-MCP-Server/tree/feature/structured-output

Let me know what you think