Once per session you can call upon this trait to determine if an action would have a positive effect or negative effect. When calling upon this ability, the GM must either answer with 'positive', 'negative', or a non-committal answer. If the third is chosen this does not expend the use of this ability as no true effect was determined.
Positive or Negative is entirely in the view of the character with this in question; what may be positive for one character may not be a positive outcome for another.