Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the behavioral burden. It conveys a read-only counting operation, but does not disclose details like whether archived, pinned, or all-shop feedbacks are included, or what exact value is returned. This is minimally adequate for a simple no-parameter count.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.