XML docs to tool definition

[NikiforovAll]

Is your feature request related to a problem? Please describe.
I want to be able to describe multi-line tool definitions.

Describe the solution you'd like
Use XML docs as a source of tool definition. Opt-in option.

Describe alternatives you've considered
Implementing as a separate NuGet package.

[eiriktsarpalis]

I think ASP.NET Core OpenAPI is doing something similar with their schema generation, however it is tricky to get right because there's no reliable way of reading XML docs other than have the application look for the XML files at runtime. It's probably easier for ASP.NET Core to do because it is a framework as opposed to a library. cc @halter73

[NikiforovAll]

@eiriktsarpalis Is there a way to dynamically add metadata for tools defined using attributes such as [McpServerTool] at startup time? This feature could be a separate package, but I don't want to limit potential consumers on how to enrich the metadata with XML comments.

[stephentoub]

[McpServerTool] is just shorthand for using McpServerTool.Create and registering that with DI, so you can programmatically use that however you like. You can also derive from McpServerTool to layer in your own behaviors, and there's a DelegatingMcpServerTool if you want to create one that wraps another (e.g. one created by Create) in order to override/augment various behaviors.

[NikiforovAll]

Thank you for pointing that out. I will review the codebase and tests to figure out how I can utilize this extensibility point.