Investigate Inconsistent Function ID in Span Attributes

[RulaKhaled]

https://huxe.sentry.io/explore/traces/?field=ai.telemetry.functionId&field=gen_ai.fu[…]2yAxes%22%3A%5B%22sum%28gen_ai.usage.total_tokens%29%22%5D%7D

ai.telemetry.functionId have different value than gen_ai.function_id

[linear]

JS-992 Investigate Inconsistent Function ID in Span Attributes

[RulaKhaled]

Two things here:

1. gen_ai.function_id should only be set for generation functions. This means it’s expected to be missing for tool spans, even though ai.telemetry.functionId exists.
2. We need to update the code so that we don’t set it only when the tool ID matches our expected pattern. The user can set the function ID at the request level, and we should respect the user’s input (it doesn’t have to include a dot). This should be resolved with fix(core): Remove check and always respect ai.telemetry.functionId for Vercel AI gen spans #17811