Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds useful behavioral context beyond annotations: it searches a lightweight static index against title, relative path, and first-paragraph summary, and returns specific fields. It does not discuss rate limits or pagination, but that is not required given the annotation coverage and simple read-only nature.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.