RAW is a slippery slope, lets take a ride. The ability does state you can discard your hand which is still there, even if empty and can even be considerd to be 0 cards(not Raw though). Its a good argument Tara allows you to discard your whole hand, even if it is empty; its a neat thing she does. If you do,though, you risk another RAW argument; that you no longer have a hand at all. It has been discarded, the special rule from Tara allowed you to get rid of it regardless, page 24 does say you hand size can change depending on special rules etc... Congrats you get the ability off by discarding what is your hand per RAW. So, how do you get your hand back? Per Raw on page 34, you have to check your hand to see if you have less than your maximum hand size, then you draw back up. Since you no longer have a hand due the ability and no rule has allowed you to redraw it, its gone. You have no hand at all, there is nothing there to refill. Getting way too RAW would actually mean that unless you discard exactly 3 cards you have to discard your whole hand and can no longer draw any cards that are required be placed in youre hand, unless you get it back.