Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so safety is covered. The description adds the useful limitation that weather is not handled yet and the intended next tool, but gives no further behavioral detail such as how incomplete inputs are treated.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.