Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden and discloses important traits: per-call billing, charge confirmation only on business success, automatic full refund on content violations, model timeouts, or generation failures, and a safety property about catastrophic backtracking. It does not cover rate limits or authentication, but the billing and failure behavior are unusually well specified.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.