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 disclose a genuinely useful destructive side effect — the temporary profile is deleted — but says nothing about what happens to open pages, whether the profile deletion is irreversible, whether it errors if no session is running, or whether a subsequent browser_start is required.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.