Spec First Mvp

Spec First MVP

Overview

Use this skill when the danger is not lack of ideas, but too much momentum too early.

The goal is to stop cyber-wishing-machine behavior by inserting one lightweight gate:

raw idea
  -> spec seed
  -> throwaway MVP probe
  -> inspect evidence
  -> go / no-go
  -> only then move to brainstorming, planning, or implementation

Rules

• Separate problem, guess, solution shape, and wishful extras before proposing implementation.
• Distill the raw idea into a spec seed first:
  • problem
  • user / context
  • first value to prove
  • explicit non-goals
  • pass / fail signal
• Propose only 1-3 throwaway MVP probes. Each probe must answer one important uncertainty.
• Prefer probes that are cheap, inspectable, and disposable:
  • one prompt plus example I/O
  • one static page or mock
  • one minimal retrieval path
  • one scoring or evaluation script
  • one tiny data flow
• Treat the first MVP as a problem probe, not as the first production version.
• After the probe, update the spec from evidence instead of expanding the original fantasy unchanged.
• Route onward only after the user can say what was learned and what should happen next.

When to Use

Use when:

• the user has one promising idea but keeps jumping straight to "just build it"
• requirements drift quickly after a polished generated artifact already exists
• the user asks for MVP, 最小验证, 先做个最小的, 先收敛一下, or 先不要赛博许愿机
• the work involves a tool, workflow, research helper, personal knowledge system, or product concept whose shape is still unstable
• the user wants a small probe or subagent prototype specifically to expose missing spec details

Do not use when:

• multiple materially different directions still need comparison; use brainstorming
• the task is already precise and ready to implement
• the main deliverable is a durable plan or spec document rather than a validation loop

Workflow

1. Triage the raw idea.

   • What problem is definitely real?
   • What part is still a guess?
   • What part is only "would be cool"?

2. Write a spec seed.

### SPEC SEED
- Problem:
- User / Context:
- First Value To Prove:
- Non-Goals For This Round:
- Pass / Fail Signal:

3. Define 1-3 throwaway MVP probes.

   • Each probe tests one risky assumption.
   • Each probe should be small enough that throwing it away is acceptable.

4. Recommend one first probe.

   • Explain why it reduces uncertainty fastest.
   • State what evidence to inspect after it runs.

5. Set the go/no-go gate.

### GO / NO-GO
- Continue if:
- Stop or reshape if:
- Open questions after probe:

6. Route forward.
   • validated enough -> brainstorming, planning-with-files, or direct execution
   • still ambiguous -> another spec-first-mvp loop

Common Mistakes

• turning the throwaway probe into a hidden full build
• keeping too many goals in the first round
• using generated polish as proof that the concept works
• comparing giant systems before the core value has been isolated
• calling something an MVP when it is still trying to validate five things at once

References

• references/spec-seed-template.md