identify-assumptions-existing

An agent skill by phuryn, from phuryn/pm-skills. Tags: brainstorming, debugging, market-analysis, product-strategy, strategy.

What it does

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.

Install

With the skills CLI, which installs into Claude Code, Codex, Cursor and other agents:

npx skills add phuryn/pm-skills --skill identify-assumptions-existing

Or copy the skill folder into Claude Code's skills directory by hand (~/.claude/skills for every project, or .claude/skills inside one):

git clone --depth 1 https://github.com/phuryn/pm-skills
cp -r pm-skills/pm-product-discovery/skills/identify-assumptions-existing ~/.claude/skills/identify-assumptions-existing

Safety box score

Grade A, minimal risk: 0 of 100 risk points, rated 2026-10-16. The grade rates what the skill and its scripts can reach on the machine of whoever installs it, across eight categories from shell execution to secrets access. How the score works.

This is a documentation-only product discovery prompt that asks the agent to analyze assumptions across value, usability, viability, and feasibility. It does not ship scripts or automation, so the main risk is limited to how the agent frames analysis rather than any direct effect on the machine, accounts, or data.

Category levels, from 0 (none) to 3 (high)
Category	Level	Why
Code & shell execution	0 (none)	No scripts, shell commands, code evaluation, or native executables are included; the only file is a markdown prompt.
Network access	0 (none)	The skill lists external "Further Reading" links, but it does not instruct the agent to fetch or send anything over the network.
Filesystem reach	0 (none)	It only reads user-provided files if present and does not specify writes, deletes, or access outside the project.
Secrets & credentials	0 (none)	There is no request to access tokens, keys, passwords, `.env` files, browser sessions, or other credentials.
Privilege & persistence	0 (none)	No sudo, service installation, shell/profile edits, or other privilege-changing actions are present.
Instruction hijack surface	0 (none)	The text contains ordinary task guidance like "Think step by step" and does not tell the agent to ignore higher-priority instructions or hide behavior.
Irreversible actions	0 (none)	It is an analysis-only skill; it does not publish, deploy, send messages, pay, book, or delete anything.
Transparency	0 (none)	There are no binaries, base64 blobs, generated installers, or unreadable artifacts; the skill is a single readable markdown file.

Before installing

No code or scripts are shipped here; verify your agent treats it as analysis-only.
Check whether your agent auto-opens the external reference links, since they are not required by the skill itself.

Rated 2026-10-16 by an automated review of 1 file from the skill's repository.

Source

Repository: phuryn/pm-skills (all skills from this repository)
Path: pm-product-discovery/skills/identify-assumptions-existing/SKILL.md
Branch: main
Updated: 2026-09-19

prioritize-assumptions — Prioritize assumptions using an Impact × Risk matrix and suggest experiments for each.
analyze-feature-requests — Analyze and prioritize a list of feature requests by theme, strategic alignment, impact, effort, and risk.
ansoff-matrix — Generate an Ansoff Matrix analysis mapping growth strategies across market penetration, market development, product development, and diversification.
brainstorm-ideas-new — Brainstorm feature ideas for a new product in initial discovery from PM, Designer, and Engineer perspectives.
identify-assumptions-new — Identify risky assumptions for a new product idea across 8 risk categories including Go-to-Market, Strategy, and Team.
monetization-strategy — Brainstorm 3-5 monetization strategies with audience fit, risks, and validation experiments.