This is best used in events like this one where you need to display variables in a skill, such as number of uses... Otherwise it doesn't update until you move the cursor off and on the item again.
Screenshot:
JavaScript:
/*:
* @plugindesc Updates the help window for displaying variables in a skills description.
* @author William TheUnproPro
*/
Window_Help.prototype.update = function() {
this.refresh();
}
Screenshot: