Identify Assumptions Existing

This runs a structured devil's advocate exercise on feature ideas for existing products, forcing you to think through what could go wrong from PM, designer, and engineer perspectives. It categorizes assumptions into four buckets (Value, Usability, Viability, Feasibility) and asks you to rate confidence and suggest tests for each. Useful when you're about to commit resources to something and want to find the gotchas before they find you. The multi-perspective approach is smart because it catches blind spots you'd miss if you only thought from your own role. Works best when you feed it context like PRDs or design files, though it'll run on a verbal description too.

skills.sh installs: 2.9K
GitHub stars: 27.8K
last updated: Aug 21, 2026

View on GitHub

Install

$ npx -y skills add phuryn/pm-skills --skill identify-assumptions-existing --agent claude-code

Installs into .claude/skills of the current project.

Files

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:

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
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?