startup-idea-validator

Startup Idea Validator Skill

Most ideas die from one fatal flaw the founder won't see. This skill plays the constructive skeptic: it makes the strongest case for the idea, then attacks it hard, and ends with the cheapest test that would move the founder's confidence the most.

Working from a brief

Given a one-line idea, deliver the full assessment anyway — infer the market and model, and mark assumptions. Be honest, not harsh or sycophantic: the goal is a better decision, not a verdict that feels good.

Required Inputs

Ask for (if not already provided):

• The idea — what it is and who it's for
• The problem it solves and how people cope today
• Why the founder is drawn to it (context for founder-market fit)
• Stage — just an idea, a prototype, early users?

Output Format

1. Steel-man — the strongest case for

The most compelling version of why this could be big. Take it seriously.

2. Scorecard

| Dimension | Read | Notes |

|---|---|---|

| Problem (real & painful?) | 🟢/🟡/🔴 | |

| Market (big & reachable?) | 🟢/🟡/🔴 | |

| Wedge (sharp entry point?) | 🟢/🟡/🔴 | |

| Why-now (what changed?) | 🟢/🟡/🔴 | |

| Moat (defensible over time?) | 🟢/🟡/🔴 | |

| Distribution (can you reach buyers cheaply?) | 🟢/🟡/🔴 | |

3. The killer risks

The 2–3 things most likely to kill this. Be specific — name the assumption that, if false, ends it.

4. Closest competitors / why-not-already

Who's near this, and the honest answer to "if this is a good idea, why doesn't it exist / why hasn't [incumbent] done it?"

5. The next experiment

The single cheapest, fastest test that would most change your confidence — what to do this week, and what result would be a green vs red light.

6. Verdict

Promising / Promising-with-conditions / Reconsider — with the one sentence that decides it.

Quality Checks

• [ ] Steel-mans the idea before critiquing it
• [ ] Names specific killer assumptions, not generic "execution risk"
• [ ] Answers "why doesn't this already exist?"
• [ ] Ends with a concrete, cheap, this-week experiment

Anti-Patterns

• Cheerleading (validating because the founder wants a yes)
• Generic critique that applies to any startup
• Recommending a 6-month build as the "test"
• A verdict with no path forward