Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries full burden but only states it 'lists' folders without disclosing behavioral traits. It doesn't mention if this is a read-only operation, potential rate limits, authentication needs, or what the output looks like (e.g., format, pagination details), leaving significant gaps.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.