Is Webex Calling for Chrome safe?

Webex Calling for Chrome scans the text of every page you visit to detect phone numbers and turn them into click-to-call links.

On all sites (except web.webex.com), the extension injects a content script that reads the page's DOM text and re-scans it on changes to find phone numbers, wrapping each match in a click-to-call tooltip. Numbers stay in the page until you click one; on click, the selected number is sent through the extension to the Webex calling window at web.webex.com/calling to place the call. No page content is transmitted off-device except the phone number you choose to dial.