Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so 'Read-only' is pure repetition of structured data and earns no credit. The remaining value is the sketch of returned content (key memories, related items, other names), but nothing is said about behavior when the entity is not found or when the name is ambiguous.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.