When I am in a Java class file, I can get context info of a certain method/attribute/etc. (in IntelliJ, this shortcut is Ctrl+Q), which is basically a short help file describing what that element does. Look at the image 1.

But when I am in an XML file, I cannot get any contextual info on any element. Look at the image 2.

How should I enable it? Do I have to download some additional Android doc (javadoc?) file?
As CrazyCoder suggested, there is no way to get such contextual info because of the lack of sources to fetch such info from. Until better times…