Panel tooltip help

Hello,

I'm building a very simple panel with literally one button that activates some action and i would like to add a tooltip, so when user hovers above that button he would be able to read what the button does. Similar as to how it is with some buttons in photoshop (see picture).

Unfortunately I don't know how to go about it. I tried adding 'title' attribute to the button, and it obviously works in browser, but fails in PS itself.

Would appreciate any help! Thank you.