For bugs in Firefox Desktop, the Mozilla Foundation's web browser. For Firefox user interface issues in menus, developer tools, bookmarks, location bar, and preferences. Many Firefox bugs will either be filed here or in the Core product. (more info)
I'm using a recent artifact build based on inbound.
The new "bookshelf" icon (looks like several books leaning against each other,
and opens to show history/bookmarks/etc) does not have a tooltip.
I think it should.