Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive and open-world behavior, so the safety profile is covered. The description adds that the result is a directory of canonical slugs plus descriptions and that filtering is optional, but says nothing about result size, ordering, or whether the full list is returned when no query is given.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.