Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare read-only, idempotent, and non-destructive behavior, so the description does not need to repeat that. It adds useful scope context about returning current/planned opportunities and knowledge articles. However, it does not disclose result volume, pagination, or ranking behavior; 3 is appropriate given 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.