I suggest you inspect the changelog and any available code for answers you’re looking for. Ensure you don’t have a malicious alternate version.
From the Firefox documentation:
https://support.mozilla.org/en-US/kb/permission-request-mess...
The extension could listen for the steps the browser takes to navigate from a link to another page. The extension could then provide new features for the content on the page.
Extensions requesting this permission might:
Detect when streamed videos are about to play and provide a download feature
Look for and prevent ad pop-ups from opening