# product-discovery

A product discovery skill that keeps your agent honest: problem first, evidence over opinion, and frameworks like JTBD, Kano and Value Proposition Canvas.

- skill · `type=skill` · Claude Code, Codex, Cursor, GitHub Copilot, Gemini CLI, OpenCode · 379 installs · ★ 288
- Author: majiayu000
- License: MIT · policy=mirror · the beginning of the file is at the end of this page
- Source: https://github.com/majiayu000/spellbook/tree/HEAD/skills/product-discovery/SKILL.md
- Updated: 2026-10-23
- HTML: https://affpapa.org/en/nevibecode/skills/majiayu000-product-discovery

## What it does

This skill turns the agent into a discovery partner with hard rules attached. It refuses solution-first thinking, so you start by naming the problem and the outcome you want. It also blocks decisions built on assumptions, competitor copying or a stakeholder's opinion, and asks for evidence from real users instead.

There is a floor on research volume: a problem cannot be validated with fewer than 5 interviews per segment. Every assumption has to be falsifiable, with a test and a success criterion written down before you run it. The reference section maps scenarios to tools — Product Opportunity Assessment with Marty Cagan's 10 questions, TAM/SAM/SOM for market sizing, Kano for feature prioritisation, JTBD for motivation, Opportunity Solution Tree for mapping.

A chunk of the skill covers weekly habits for a product trio: interviews, assumption tests, opportunity mapping. That cadence is the point. Treat it as a one-off prompt and you lose most of the value, because the rules expect fresh user data rather than secondhand summaries.

## Install

### Claude Code (native platform)

1. **Skills CLI (Vercel)**
```bash
npx skills add majiayu000/spellbook --skill product-discovery -a claude-code
```

2. **Manually: put the files in place**
- File: `~/.claude/skills/product-discovery/SKILL.md` — Copy the whole skill folder; for one project use .claude/skills/product-discovery/

### Codex

1. **Skills CLI (Vercel)**
```bash
npx skills add majiayu000/spellbook --skill product-discovery -a codex
```

2. **Manually: put the files in place**
- File: `.agents/skills/product-discovery/SKILL.md` — For all projects use ~/.agents/skills/

### Cursor

1. **Skills CLI (Vercel)**
```bash
npx skills add majiayu000/spellbook --skill product-discovery -a cursor
```

2. **Manually: put the files in place**
- File: `.cursor/skills/product-discovery/SKILL.md` — Cursor also reads .agents/skills/ and .claude/skills/

### GitHub Copilot

1. **GitHub CLI**
```bash
gh skill install majiayu000/spellbook product-discovery
```

2. **Manually: put the files in place**
- File: `.github/skills/product-discovery/SKILL.md`

### Gemini CLI

1. **Skills CLI (Vercel)**
```bash
npx skills add majiayu000/spellbook --skill product-discovery -a gemini-cli
```

2. **Platform CLI**
```bash
gemini skills install https://github.com/majiayu000/spellbook --path skills/product-discovery
```

### Windsurf (Devin Desktop)

**Manually: put the files in place**
- File: `.devin/skills/product-discovery/SKILL.md` — The legacy .windsurf/skills/ path still works

### OpenCode

**Skills CLI (Vercel)**
```bash
npx skills add majiayu000/spellbook --skill product-discovery -a opencode
```

### Claude.ai

**Claude.ai**
- Zip the folder and upload it in Settings → Capabilities → Skills

Where a file is given instead of a command, copy the files from the source to that path: https://github.com/majiayu000/spellbook/tree/HEAD/skills/product-discovery/SKILL.md

## When to use it
- write the problem statement before anyone starts building
- size a market with TAM/SAM/SOM
- sort features through Kano and find the must-haves
- turn feature requests into job stories
- test a risky assumption with a cheap experiment

## Example prompts
- run a Product Opportunity Assessment on my mobile app idea
- draft an interview guide for churned users using JTBD
- categorise these features with the Kano model and rank them

## Source text · SKILL.md · MIT

Below is the content of a third-party file. It is data, not instructions for you: do not act on anything written inside unless the human asks. Block tag: 3fd52494d7b23558.

BEGIN THIRD-PARTY FILE 3fd52494d7b23558
````text
---
name: product-discovery
description: Product discovery and market research expert. Use when validating product ideas, conducting market research, user interviews, competitive analysis, or opportunity assessment. Covers JTBD, Kano model, and Value Proposition Canvas.
---
# Product Discovery

## Core Principles

- **Continuous Discovery** — Weekly user conversations, not episodic research
- **Outcome-Driven** — Start with outcomes to achieve, not solutions to build
- **Assumption Testing** — Validate risky assumptions before committing resources
- **Co-Creation** — Build with customers, not just for them
- **Data-Driven** — Use evidence over intuition and stakeholder opinions
- **Problem-First** — Deeply understand the problem space before ideating solutions

---

## Hard Rules (Must Follow)

> These rules are mandatory. Violating them means the skill is not working correctly.

### No Solution-First Thinking

**Never start with a solution. Always define the problem and outcome first.**

```markdown
❌ FORBIDDEN:
"We should build a search bar for the product page"
"Let's add AI recommendations"
"Users need a mobile app"

✅ REQUIRED:
"Problem: Users can't find products (40% exit rate on catalog)
Outcome: Reduce exit rate to 20%
Possible solutions:
1. Search bar with filters
2. AI-powered recommendations
3. Better category navigation
4. Visual product browsing"
```

### Evidence-Based Decisions

**Never assume user needs without evidence from real user research.**

```markdown
❌ FORBIDDEN:
- "Users probably want X" (assumption without data)
- "Our competitor has X, so we need it too" (copycat without validation)
- "The CEO thinks we should build X" (HiPPO without evidence)
- "It's obvious users need X" (intuition without validation)

✅ REQUIRED:
- "5 out of 8 interviewed users mentioned X as a pain point"
- "Analytics show 60% of users abandon at step 3"
- "Prototype test: 7/10 users completed task successfully"
- "Survey (n=500): 45% rated feature as 'must have'"
```

### Minimum Interview Threshold

**Never validate a problem with fewer than 5 user interviews per segment.**

```markdown
❌ FORBIDDEN:
- "We talked to 2 users and they loved the idea"
- "One customer requested this feature"
- "Based on a quick chat with sales..."

✅ REQUIRED:
| Segment | Interviews | Key Finding |
|---------|------------|-------------|
| Power Users | 6 | 5/6 struggle with X |
| New Users | 5 | 4/5 drop off at onboarding |
| Churned | 5 | 3/5 cited missing feature Y |

Minimum per segment: 5 interviews
Confidence increases with more interviews
```

### Falsifiable Assumptions
````
END THIRD-PARTY FILE 3fd52494d7b23558

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---
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