question: trait functions as tool calls

[ssddOnTop]

Say if I've a trait:

trait Tool: Sized + Send + Sync + 'static {
    fn foo(&self, x: i32, y: i32);
    fn bar(&self, x: i32, y: i32);
}

Is there any way that I can treat functions foo and bar as tool calls?

I was checking the calculator example and on line 37 there is #[tool(tool_box)] implemented on a trait, but I can't directly do that on my Tool trait. So is there any way to directly treat a trait as a set of tool calls? Or is there any way to set the implementation of the trait as a tool call?

[jokemanfire]

Line 37 is not actually a toolbox for defining the target using macros, but rather a macro expansion of the traits (ServerHandler) that the target service needs to implement. Unfortunately, it is not currently possible to directly define traits as toolboxes.

[ssddOnTop]

@jokemanfire The macro implementation is messed up. It works, but it's hard to modify. But that's not the main concern.

I am worried that the current design for macros implementation is not quite intuitive, it's confusing why we need to implement some macro atop of the ServerHandler implementation to a struct, and why it needs a new function.

I think, we should expose more traits for users to implement instead of macros which should be intuitive, and there should just be a single macro or several macros with minimal attribute arguments. And the functions that we want to expose as tool should work well with traits, it should not generate additional code or functions (like we generate _tool_attr and _tool_call right now).

[jokemanfire]

@4t145 cc

[4t145]

Personally I don't like the marco way to implement features either, but people who migrate from python do want some macro like fastmcp. So I want to give out a progressive API, for people who want a complicated feature, they can implement and add handlers manually. And for people who want implement call_tool and list_tool themselves, they can use a tool box to add a function as a tool easily by using toolbox api. And for people who want a quick implementation, they can use a combination of toolbox and tool macro.

I have to admit that the current implementation is not good enough, and I am also interested in making a better implementation later.