Tool call arg counts for Gen AI tool call spans

[michaelsafyan]

Area(s)

area:gen-ai

What's missing?

There isn't yet a convention for reporting a summary of the arguments.

A summary of the arguments is useful where the details might be omitted.

Describe the solution you'd like

I'd like the following span attributes defined:

• gen_ai.tool.positional_args.count
• gen_ai.tool.keyword_args.count

[michaelsafyan]

There is a draft PR related to Google Gen AI SDK instrumentation that illustrates how this might be used:

• feat(google-genai): add instrumentation to supplied tool call functions opentelemetry-python-contrib#3446

[aabmass]

What if we capture the parameter names and parameter numbers.

For DB conventions, it's been like this.

[matt-hensley]

From footnote 5 in the db attributes:

db.operation.parameter: If a parameter has no name and instead is referenced only by index, then SHOULD be the 0-based index.

And the keys are used to make an attribute per parameter like db.query.parameter.<key>

[lmolkova]

Maybe we should consider providing a signature foo(bar: string, baz: Any) ?

or

code.function.arg.{key}:
code.function.arg.0 = "*"
code.function.arg.foo = "*"