Good Morning Toad Team,
Just noticed this today in version 12.11, but same issue exists in latest 220.127.116.11 beta. Describe window does not have right click add to Schema Browser Favorites. To reproduce highlight a table name anywhere and press F4. The describe window will open. Right click the table name in the describe window, hover over Add and the bottom entry "to Schema Browser Favorites" is not on the list, like it is in the schema browser.