Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and openWorldHint=true, so the safety profile is covered. The description contributes the concrete contents of the response (title, intro copy, visibility, customization), which is useful. It adds nothing about permissions, rate limits, or defaults, so it neither contradicts nor significantly enriches the annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.