In QtCreator editor while navigating to any name the balloon help appears with additional info. If it is Qt's system var or function then extended info is shown in balloon basement. But if it is project defined variable - then only it's type is shown. I suggest show in balloon all commented text after the var is exists. For example if var definition is:

int ihs; // item's horizontal size

balloon will contain text " item's horizontal size" in balloon when navigating cursor to any ihs usage in code. Similar if function prototype is

bool procFunc(int value, QString& str); // processes str with limit, 
                                        //returns true when success

balloon will contain text "processes str with limit, returns true when success"