Pressure-test a startup idea the way a sharp investor or co-founder would — problem, market, wedge, moat, why-now, and the fastest cheap way to test it. Use when asked to validate a startup idea, evaluate a business idea, stress-test a concept, or decide whether something is worth building. Produces an honest assessment with the strongest case, the killer risks, and the next experiment to run — not cheerleading.
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Use startup-idea-validator to pressure-test [idea, audience, and problem/current workaround] given [founder context and stage], delivering the strongest case, specific killer assumptions, closest competitors, and one cheap test to run this week.
Required inputs
[idea, audience, and problem/current workaround]
[founder context and stage]
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SKILL.md
name: startup-idea-validatordescription: "Pressure-test a startup idea the way a sharp investor or co-founder would — problem, market, wedge, moat, why-now, and the fastest cheap way to test it. Use when asked to validate a startup idea, evaluate a business idea, stress-test a concept, or decide whether something is worth building. Produces an honest assessment with the strongest case, the killer risks, and the next experiment to run — not cheerleading."
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)