Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden, but it only implies a read/poll operation. It does not disclose whether the call is read-only, whether it errors for datasets not yet created, what status values can be returned, or whether a creation/update must be initiated first.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.