Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety bar is low. The description still adds value by noting the content can be served through an 'authenticated immutable version resource' and that full content is returned inline, which tells the agent about auth requirements and version immutability.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.