Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations alrady provide readOnly/openWorld/idempotent/hon-destructive, so the bar is lower. The description adds valuable behavior: no API key needed, returns a matched subset, case-insensitive filtering, and network preference. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.