I stopped guessing about a useful second-opinion prompt

Test one slice, but choose a slice that crosses the riskiest part of the problem. A tiny easy demo will only prove the easy part.

Use this decision rule:

• If reversing the choice is cheap, try it.
• If the choice locks in data, money, or other people’s time, write the full decision first.
• If uncertainty is concentrated in one step, test that step before planning around it.

For a useful second-opinion prompt, make the first test produce evidence you can compare, not just something that looks complete.