Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so 'Read-only and safe to repeat; it changes nothing' is largely redundant with structured data and earns little credit. What it does add is return behavior ('best matches with page links'), which matters because there is no output schema, though ranking/ordering and result-limit behavior remain undisclosed.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.