The Android SDK is well documented with examples throughout and hyperlinked to examples and posts which explain some content in greater depth.
For example, I remember getting frustrated because of the docs for a setTextSize method, with the helpful description “sets the text size”. Nice. Very helpful that it didn’t mention what unit the parameter was, especially since (after experimentation) it turns out the unit is not the one you would expect for a font size.
The API docs were full of that kind of ‘documentation’, setX: “Sets X”.
If you are writing documentation, please explain what method parameters and return values actually mean, what the units used are. Especially if uses a unit no one expects. For example: font sizes are usually specified in points, if you expect them to be specified in pixels you should absolutely mention that.
I think this is particularly a problem with Java docs because Java IDEs auto-insert useless documentation and people think "oh great it's documented".