Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover key behavioral traits (readOnlyHint=true, destructiveHint=false, idempotentHint=true), so the bar is lower. The description adds useful context about returning matches with surrounding context, but doesn't mention rate limits, authentication needs, or error conditions.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.