Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, openWorldHint, and destructiveHint=false, so the safety profile is covered structurally. The description adds the useful behavioral trait that matching is fuzzy (not exact) and spans all models at once, but says nothing about result caps, ranking, or whether results respect the caller's permission scope.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.