Simple addon that sets debuff border to red for DoTs and debuffs that does damage to you or in any other way will break your stealth. This makes it super easy for sh!t arena players like me, to quickly glance my debuffs to see if I can vanish safely or not, or if I have to cloak.
In this example you can see that only the debuffs that are doing damage to you is marked red. 
How I decide if a debuff will break stealth:
First check if buff is a player debuff. Then parse the tooltip string for the debuff. Check if the string contains any of the following words:
- "every"
- "over"
- "per"
- "after"
- "bleeding"
- "flare"
If the debuff tooltip contains any of those words, we set the border color to red. If not we set the border color to clear/none