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