Use separate `args` argument for `tool()`

[hadley]

And check that the length + names match the function.

[gadenbuie]

Just a small note that it is occasionally useful to hide an argument from the LLM (which requires that that argument is assigned a default value).

[hadley]

Ok, subset of then.

[hadley]

@gadenbuie how common do you think that is? Because only checking that the arguments are a subset of the formals really weakens the check. What if we let you specific NULL to indicate that the argument shouldn't be accessible to the LLM?

[hadley]

Should we also check that the name doesn't include special characters?

[gadenbuie]

how common do you think that is?

I think it's more likely to be something you want to do when you're wrapping a packaged user-facing function and you want to constrain the options given to the LLM.

What if we let you specific NULL to indicate that the argument shouldn't be accessible to the LLM?

I think that's a good compromise. One could also wrap the function with only the arguments shown to the LLM.

I agree that the stronger checks will be more useful and I think the benefit of the checks outweighs the inconvenience. After thinking about this more, I'm slightly more in favor of requiring a partial or a wrapper so that all argument are specified over the NULL to hide the argument from the LLM.