Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
While annotations already cover read-only, open-world, idempotent, and non-destructive aspects, the description goes well beyond by disclosing key behavioral traits: deterministic by CBSA, no API key required, and the crucial data-lag caveat that figures are a 5-year rolling average with an exact release date. This adds substantial operational context beyond what annotations provide.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.