Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Goes well beyond the annotations by disclosing that this is an asynchronous run that takes about a minute and returns a run_id for polling, plus concrete rate limits (two a day per address) and tiered allowances. The annotations only flag non-read-only, non-idempotent, open-world; the description supplies the operational context an agent actually needs.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.