Cagan's opportunity assessment is a short list of questions a team answers before it commits to building. Which pair opens it?

The principle — the assessment is a set of questions asked before effort is spent, not a report written after it.

Why the key is correct — Cagan's list opens with Exactly what problem will this solve? (value proposition) and For whom do we solve that problem? (target market) A team that cannot say what problem it is solving, and for whom, has nothing the rest of the list can build on.

Why the others are wrong — a signed-up buyer is a later commercial fact. Describing what was built turns the exercise into a retrospective, which is the one thing it is not. And launch metrics arrive after the decision the assessment exists to inform.

Remember this — the problem and the person come first, and both are answerable before anything is built.

Sources — Marty Cagan on assessing product opportunities, Silicon Valley Product Group.