Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Beyond the readOnly and idempotent annotations, the description discloses operational behavior: jobs take 1-5 minutes, the call answers once after waiting, repeated calls are needed until allFinal, and an unknown id fails only for itself. These are meaningful traits an agent needs before invoking it.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.