Higher than necessary!

Dealer East, All Vul.

Sitting East, you are the dealer and hold the following hand:

You open a natural 1♥, over which South overcalls 1NT and North raises to 3NT:

You are not surprised to see your partner lead the ♥8…

How many high card points does partner have?

You see 12HCP (your hand) + 8HCP (dummy) + 15 to 17HCP (South) = 35 to 37HCP, leaving 3-5 for West. It would be perfect if he had the Heart 8 doubleton and the Diamond Ace (assumptions of necessity), as this would allow your side to thwart the exploitation of dummy’s long suit. Declarer covers with the Heart 9.