Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits. It only states the action but omits important details: whether it returns a boolean/status code, authentication requirements, rate limits, or behavior for non-existent users. The minimal description does not add value beyond the obvious.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.