Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Without annotations, the description carries full burden. It discloses the scope (up to 36 measures) and parameter behavior (omit year for most recent), but lacks details on error handling, authentication, rate limits, or what happens on invalid FIPS code.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.