Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With annotations already declaring readOnlyHint, idempotentHint, and destructiveHint=false, the description adds meaningful behavioral detail by specifying the two invocation modes and what each returns (index vs full content). It doesn't contradict annotations and provides additional context beyond them.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.