write-spec

Writes structured feature specs with goals, non-goals, P0 requirements, and success metrics.

Updated Jul 21, 2026
One-click install
npx skills add https://github.com/BrunoL28/product-onboarding-skill --skill write-spec-brunol28
Or copy as Structured Prompt for Agent▼
Please help me install this Agent Skill.
Skill: write-spec
Source: https://github.com/BrunoL28/product-onboarding-skill/tree/main/skills/write-spec
Command: npx skills add https://github.com/BrunoL28/product-onboarding-skill --skill write-spec-brunol28

SYSTEM DOCUMENTATION & REQUIREMENTS

What problem does it solve? Turning a vague feature idea or user request into a document an engineer can estimate and a stakeholder can argue with is slow and inconsistent. This Skill produces a structured feature spec with measurable goals, reasoned non-goals, prioritized requirements, and falsifiable success metrics, so scope debates happen on paper instead of in sprint planning. ## Core Features & Use Cases - Structured spec generation: Produces eight fixed sections — Problem Statement, Goals, Non-Goals, User Stories, P0/P1/P2 Requirements, Success Metrics, Open Questions, and Timeline — following a stable output template. - P0 challenge protocol: Runs three questions on every must-have requirement and demotes anything that is not genuinely blocking, regulatory, or journey-breaking. - Artifact-first intake: Reads upstream discovery artifacts (problem statement, persona, Lean UX canvas, story map) before asking questions, so the spec cites discovery instead of rewriting it. - Use Case: A product manager has a validated problem statement and Lean UX canvas for a card-dispute feature. The Skill collapses those artifacts into a spec, demotes two of six proposed P0s, flags an estimated baseline as needing instrumentation, and routes a regulatory wording question to legal as blocking. ## Quick Start Ask the assistant to write a spec for your feature idea, pointing it at any existing problem statement, persona, or Lean UX canvas files so it can pre-fill the document.

Frequently Asked Questions about write-spec

High-intent search queries and answers about installing and using this skill.

FAQPage Schema
How do I write a feature spec from a vague idea?▼

Provide the feature idea plus the user problem, target users, and success criteria. The Skill asks at most three targeted questions, then produces a structured spec with goals, non-goals, prioritized requirements, and metrics, labelling any gaps as assumptions.

What is the difference between a feature spec and a PRD?▼

A spec scopes one feature with goals, requirements, and acceptance criteria. A PRD covers a whole initiative including architecture, ADRs, and non-functional requirements. For full initiatives, use the prd-development skill instead.

How does the P0 challenge protocol work?▼

Every P0 requirement faces three questions: what breaks without it, whether the core journey works without it, and whether a regulation or hard dependency requires it. Requirements that fail are demoted to P1 or P2, and the outcome is recorded in the spec.

Can the spec reuse existing discovery documents?▼

Yes. The Skill reads upstream artifacts like PROBLEM_STATEMENT.md, PROTO_PERSONA.md, LEAN_UX_CANVAS.md, and USER_STORY_MAP.md first, reports what it found and inferred, and only asks about genuine gaps rather than re-deriving existing work.

What are the limitations of this spec-writing approach?▼

It does not produce engineering estimates, design decisions, or committed deadlines, and it will not invent metric baselines or regulatory requirements. Unmeasured baselines are flagged as needing data, and legal questions are routed to an owner as blocking.