Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnly, openWorld, idempotent, and non-destructive behavior, lowering the burden on the description. The description adds that the return format is markdown, which is useful, but does not disclose other behavioral details such as error handling or empty results. This meets the baseline with some added value.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.