Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral disclosure burden. It explains that the list is dynamic and reflects actual availability, and it explicitly prohibits guessing model names — a meaningful behavioral guardrail. It does not mention read-only status or failure behavior, but for a listing tool the key behavior is well covered.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.