Actually, the information is very much possible. GAE now has support for tooltips on mods, and the magitech that comes bundled with GAE will have those available. Of course, they are a bit more complex (a lot, actually) since the tooltips are located in a separate language file, and are referenced from by "tip" tags in the unit's XML, but generally located on the command where units are created (such as build commands and produce commands) instead of the actual unit's XML.