Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
There are no annotations, so the description carries the burden of behavioral disclosure. The description discloses that closing the browser frees resources and that the saved session enables automatic reopening. This is useful beyond a bare 'closes the session' phrase. It did not mention impact on unfetched/unsubmitted work or irreversible actions, but for a clean-session-close operation that auto-reopens a exactly-saved state, this is adequate.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.