Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It discloses the scoring thresholds, the data sources combined, and the authentication/tier requirement. The verb 'get' signals a read-only operation, though it doesn't explicitly state rate limits or absence of side effects; the output schema covers return shape.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.