Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly/idempotent/non-destructive, and the description adds genuinely new behavioral facts: results come from deps.dev, the scope is direct (not transitive) dependencies, and version defaults to latest. It omits rate limits and result shape, but the output schema covers the latter.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.