Keen Sense

• WWizards of the Coast2018-03-16
  Official Ruling
  You draw one card each time the enchanted creature deals damage to an opponent, no matter how much damage it deals or whether it was dealt in combat.
• WWizards of the Coast2018-03-16
  Official Ruling
  If this Aura enchants an opponent's creature, you won't draw a card when that creature damages you. The creature has to deal damage to one of your opponents for the ability to trigger.

Rulings via Scryfall