I think the extent of your contribution will become clear if you stick around.

Something else to consider - maybe the board is ecstatic because it's not actually solving the right problem but looks very streamlined? You say the boss was only giving you one sentence saying what to build.

I don't know how well requirements were communicated in those sentences, but if they told you exactly what you needed to know, I'd say your boss has done a very good job, along with you.

EDIT: I want to say that it sounds like you and your boss are a great team. Don't screw that up over your apprehensions right now. See how it goes.