I am new to Linux in general and would like to know if it's possible to add a comment to an icon/application shortcut so that when I hover over it, a short preview of what the application does shows.

I have googled and checked forum posts on ubuntu.com but they mention Unity. Does Kali use Unity?

My rationale behind this is when browsing the "start menu" and say I'd hover over Metasploit, I would like to know what this application does without going online to http://tools.kali.org/tools-listing and browsing for the tool.

Thank you for the help