Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive, and closed-world behavior, so the safety profile is covered. The description adds useful specifics beyond that: the catalog includes endpoints and capabilities, filtering is case-insensitive, and omitting the filter returns everything. It stops short of noting any rate limits or catalog freshness, which is acceptable for a simple read tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.