Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden and does well: it discloses the default verdict ('keep'), the overwrite semantics ('the last verdict wins'), the note length cap (280 chars), the enumerated reason values, and that the operation is 'Free'. It omits auth/permission behavior despite an api_key parameter existing, which keeps it out of the top band.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.