Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. "Mutates Feedbin state" is better than nothing, but it restates what "create" already implies and reveals nothing about validation of the query, whether duplicates are allowed, whether the response returns the new ID, or error/permission behavior.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.