Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations at all, the description must disclose side effects, output behavior, and access requirements, but 'Full State Snapshot' says nothing about whether the operation is read-only, what format is returned, whether data is persisted, or whether it requires special privileges. This is a total gap in behavior disclosure for a no-annotation tool.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.