Success
If you succeed at a saving throw against an effect that has no obvious physical indications, you feel a hostile force or a warning tingle but cannot deduce the exact nature of the attack. Likewise, if a creature specifically targeted by one of your effects succeeds at its saving throw, you can generally tell that the creature has succeeded. You do not sense when creatures succeed at saves against effects you create that don’t target a single creature.
Source
Core Rulebook pg. 242
