Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare a non-read-only, open-world, non-destructive operation, so the bar is lower. The description adds genuinely non-structured context: a 10-credit cost and the fact that execution is asynchronous returning a project id, both of which materially affect how an agent invokes it.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.