Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already establish read-only, idempotent, open-world, non-destructive. The description adds genuinely useful operational traits beyond them: access/delay/metered usage tied to the connected account, a single bounded request with no polling or retry, and no wagers/account changes. It doesn't state rate limits or pagination, so a 4 rather than 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.