In order to ease and improve the BDD tests on PlatformUI there should be appropriate HTML tags/class attributes. These tags should help identify the various elements present in the page in a logic and meaningful way.

In this case we could use is identifiers for everything related to RichText.
For example the big round add button even though it as a class 'ae-button-add' it would still be better to have a unique BDD related identifier. The most important one would be the other buttons from alloy editor since most of them only have a 'ae-button' class and we have to resort to other attributes such as the element title.
IMO instead of a class we could have sort of a attribute in the elements only for the BDD tests maybe it would not pollute the class attribute, but I leave that to your criteria.