Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds that the returned schema covers both request AND response, which is useful beyond the annotations and beyond the short output schema summary. It says nothing about lookup failure behavior or that the 'method' parameter affects which schema is returned.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.