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identify-assumptions-existing — Claude Code skill: how to install
This skill stress-tests feature ideas in existing products across four risk areas. It uncovers blind spots through the eyes of a product manager, designer, and engineer.
Install into Claude Code · Skills CLI (Vercel)
All methods and platforms ↓
npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a claude-codeWhat identify-assumptions-existing does
The skill acts as a devil's advocate when evaluating a new feature for an existing product. You provide your product description, goal, market segment, and feature idea, or attach PRD files. The assistant reviews those documents first. It then examines failure risks across product, design, and engineering perspectives. This catches blind spots before coding begins.
Risky assumptions are grouped into four areas: value, usability, viability, and feasibility. For each assumption, the skill notes failure scenarios, confidence scores, and testing methods. Without context, the output stays generic. Detailed product input is therefore essential here.
What it helps with
- stress-test a new feature idea against four risk categories
- surface hidden assumptions before writing any code
- review potential failure modes across product, design, and engineering roles
- prepare structured input for assumption mapping and validation tests
Example prompts for the agent
- Stress-test this new bulk export feature for our B2B dashboard using our attached PRD
- Identify assumptions for adding automated billing reminders to our mobile app
How to install identify-assumptions-existing
1Skills CLI (Vercel)
npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a claude-code2Manually: put the files in place
~/.claude/skills/identify-assumptions-existing/SKILL.mdCopy the whole skill folder; for one project use .claude/skills/identify-assumptions-existing/
1Skills CLI (Vercel)
npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a codex2Manually: put the files in place
.agents/skills/identify-assumptions-existing/SKILL.mdFor all projects use ~/.agents/skills/
1Skills CLI (Vercel)
npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a cursor2Manually: put the files in place
.cursor/skills/identify-assumptions-existing/SKILL.mdCursor also reads .agents/skills/ and .claude/skills/
1GitHub CLI
gh skill install phuryn/pm-skills identify-assumptions-existing2Manually: put the files in place
.github/skills/identify-assumptions-existing/SKILL.md1Skills CLI (Vercel)
npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a gemini-cli2Platform CLI
gemini skills install https://github.com/phuryn/pm-skills --path pm-product-discovery/skills/identify-assumptions-existingManually: put the files in place
.devin/skills/identify-assumptions-existing/SKILL.mdThe legacy .windsurf/skills/ path still works
Skills CLI (Vercel)
npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a opencodeClaude.ai
Zip the folder and upload it in Settings → Capabilities → Skills
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Questions about identify-assumptions-existing
How do I install identify-assumptions-existing in Claude Code?
Run npx skills add phuryn/pm-skills --skill identify-assumptions-existing -a claude-code in your terminal.
What does identify-assumptions-existing do?
It acts as a constructive devil's advocate, identifying risky assumptions in feature ideas across value, usability, viability, and feasibility.
What inputs does this skill require?
Provide your product description, target market segment, goal, and feature concept, plus any existing PRD, design, or research files.
Source text
SKILL.md · MIT
--- name: identify-assumptions-existing description: "Identify risky assumptions for a feature idea in an existing product across Value, Usability, Viability, and Feasibility. Uses multi-perspective devil's advocate thinking. Use when stress-testing a feature idea, doing risk assessment, or preparing for assumption mapping." --- ## Identify Assumptions (Existing Product) Devil's advocate analysis to surface risky assumptions across four risk areas. ### Context You are stress-testing a feature idea for **$ARGUMENTS**. If the user provides files (designs, PRDs, research), read them first. ### Instructions The user will describe their product, objective, market segment, and feature idea. Work through these steps: 1. **Think from three perspectives** about why this feature might fail: - **Product Manager perspective**: Business viability, market fit, strategic alignment - **Designer perspective**: Usability, user experience, adoption barriers - **Engineer perspective**: Technical feasibility, performance, integration challenges 2. **Identify assumptions across four risk areas**: - **Value**: Will it create value for customers? Does it solve a real problem? - **Usability**: Will users figure out how to use it? Is the learning curve acceptable? - **Viability**: Can marketing, sales, finance, and legal support it? - **Feasibility**: Can it be built with existing technology? Are there integration risks? 3. **For each assumption**, note: - What specifically could go wrong - How confident you are (High/Medium/Low) - Suggested way to test it Think step by step. Be thorough but constructive — the goal is to strengthen the idea, not kill it. --- ### Further Reading - [Assumption Prioritization Canvas: How to Identify And Test The Right Assumptions](https://www.productcompass.pm/p/assumption-prioritization-canvas) - [How to Manage Risks as a Product Manager](https://www.productcompass.pm/p/how-to-manage-risks-as-a-product-manager) - [Continuous Product Discovery Masterclass (CPDM)](https://www.productcompass.pm/p/cpdm) (video course)
© phuryn · MIT · phuryn/pm-skills
