Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already include readOnlyHint=true, so the read-only behavior is disclosed. The description adds context about the content brevity ('condensed 2-minute guide') and scope (minimal examples, core syntax), which helps set expectations about the return value. No contradiction with annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.