Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already include readOnlyHint=true and idempotentHint=true, so the description doesn't need to repeat that. It adds the ranking by relevance behavior but does not mention any limits (e.g., number of results, pagination). With annotations covering the safe-read nature, a 3 is fair as it adds some but minimal extra behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.