Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, and openWorldHint=false, so the safety profile is covered. The description adds useful non-annotation context: the output is a TOC grouped by category, entries carry page ids consumable by `fetch`, and the category filter narrows the listing. It doesn't mention pagination or size limits, keeping it below a 5.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.