1NT is 15-17..so it turns out that there is not an obvious call here. We had some discussion in the club as well, without any relevant conclusions, except that this card is a pass. I've doubled at the table, but after taking all the answers into account, I think I'm leaning towards passing in a similar situation next time. And yet I'm not sure whether the double should be short in spades (I believe I should be holding clubs) and showing hearts and diamond tolerance, or suggesting partner to leave it in with some defensive strength...