Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, so the description doesn't need to reiterate safety. It adds meaningful context by explaining the return payload (score, band, confidence, top drivers) and the data source/scope, which goes beyond the annotations. However, it doesn't disclose potential edge cases like invalid ZIP formats or unavailable data.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.