AddOn descriptions in the store cannot be expanded. User has no idea what an AddOn does unless they accidentally hover and read.

Screenshot:

At the end of the description there's an elipses, indicating more available info. Nowhere on this screen is a clickable link to get more information. Instead, the user must hover over the description, wait, and then read. This not obvious to the user and unexpected; so much so that it's entirely possible for the user to give up before realizing how to get the info.