Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full transparency burden. It discloses that it returns one record per county, specifies the year range coverage, and explains parameter defaults (e.g., county_fips omitted returns all counties). It doesn't address error handling or auth, but for a read-only data retrieval tool, the core 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.