Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It does not say whether this is a safe read or a destructive/stateful operation, whether the snippet is returned inline or written to disk, whether recording must be stopped first, or what happens with an empty/invalid session.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.