Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/idempotent/non-destructive, so the lower bar applies, and the description still adds real value: the exact token scheme ('Authorization: Bearer hodds_...') and the concrete failure mode ('token_required'). It doesn't mention volume, pagination, or ordering of the returned list, which keeps it from a 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.