[BUG]: AI SDK `experimental_telemetry.functionId` is ignored

[carlmw]

Tracer Version(s)

5.64.0

Node.js Version(s)

20.19.0

Bug Report

Not sure if this is truly a bug/oversight or really a feature request.

In https://ai-sdk.dev/docs/ai-sdk-core/telemetry#telemetry-metadata there is mention of a functionId.

When using an OTel tracer this is used to form the name of the span — which i've verified.

Expected
The span has a name my-cool-span

Actual
The span has the default name generateText

Perhaps there is a work around for this or some documentation somewhere for how to set the span name through dd-trace?

Reproduction Code

await generateText({
  model: openai("gpt-4o-mini"),
  prompt: "What is best in life?",
  experimental_telemetry: {
    isEnabled: true,
    functionId: 'my-cool-span'
  }
})

Error Logs

No response

Tracer Config

No response

Operating System

Darwin Kernel Version 24.6.0

Bundling

No Bundling