I like the idea but I'm not sure if there's an ideal cost for this card. I think this is better than Coercion, although I'm not really sure how much better. For reference:
Coercion


Sorcery
Target opponent reveals his or her hand. Choose a card from it. That player discards that card.
This has a converted mana cost of 1 less, but has 2 colours in the mana cost. Furthermore, this allows the opponent to reveal less than his or her entire hand, but there's a drawback for doing so. I'm tempted to suggest you up the cost to



, but I'm not sure that's necessary. I suppose this gets my seal of approval. I can't really find anything grossly wrong with the card and, it being kind of late I'm probably in no condition to nitpick.