shady joker:
They are vague on purpose. WoD and all Story Teller games are about story and role play, not hard numbers. Each Story Teller/GM is supposed to sit down with their player and establish what Mentor or Favors actually does in the game.
I know that they are vague on purpose, but same was the case with spells in first two editions of Mage: The Ascension. It didn't work, because you need to know how much damage your spell inflicts. Now if I cast a spell I know how much damage it does, but when I summon an archangel to cast a spell for me I have no idea how powerful it will be. That doesn't make sense.