When you place the mouse pointer over any Qt function/class it shows a pop-up with short description of what it does, taken from the docs in the comment above the function/c
Qt Creator requires the generated docs to have some special markers in order to retrieve the tooltip text. I couldn't find a way to insert these markers with Doxygen so I've created a simple script to do it:
https://github.com/mmmarcos/doxygen2qtcreator
It's not bulletproof but it allows us to integrate our classes and methods briefs into Qt Creator tooltips.