Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already convey non-read-only, non-idempotent, and open-world nature. The description adds useful context: it uses the project's configured repo/assignee unless overridden and embeds the AI prompt in the body, which goes beyond the annotations without contradiction.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.