Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover read-only, idempotent, and non-destructive behavior. The description adds meaningful operational context: the 10-credit cost, automatic slug/URL resolution at no extra cost, and the ability to skip lookup by providing an id from companies_entity_id. There is 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.