Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations only indicate this is not read-only, not idempotent, and not destructive; the description adds no side-effect information such as whether a test is immediately triggered, whether a report is created, or whether the operation is asynchronous. Since annotations are minimal, the description carries the burden and does not satisfy it.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.