[Bug - Agent Analytics] Time to First Token vs Total Time

[putrasyafiq]

Describe the bug
I've noticed that in the BigQuery Agent Analytics Plugin, the time to first token vs the total time taken under the latency metrics is always exactly the same. This causes some discrepancies when implementing observability.

To Reproduce

1. Install the BigQuery Agent Analytics Plugin.
2. Run an LLM prompt.

Expected behavior
Expected the time to first token (ms) to be lesser than total time taken.

Screenshots

Environment

• OS: Linux
• Python version(python -V): 3.13.7
• ADK version(pip show google-adk): 1.22.1