Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint, idempotentHint, destructiveHint=false, openWorldHint=false). The description adds a useful behavioral trait — the hard cap of three results and the literal (non-semantic) matching — but says nothing about the two corpora, match failure behavior, or result shape beyond what the output schema carries.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.