Borrowing it
Nothing to install: this file belongs to lglucas/ai-dev-operating-system. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/lglucas/ai-dev-operating-system/main/.claude/skills/product-brief/SKILL.mdgit clone --depth 1 https://github.com/lglucas/ai-dev-operating-systemWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/lglucas/ai-dev-operating-system/product-brief)<a href="https://agentmods.dev/skills/lglucas/ai-dev-operating-system/product-brief"><img src="https://agentmods.dev/badge/skills/lglucas/ai-dev-operating-system/product-brief/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/lglucas/ai-dev-operating-system/product-brief"><img src="https://agentmods.dev/badge/skills/lglucas/ai-dev-operating-system/product-brief.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00109 | $0.00406 |
| Opus 5 | $0.00055 | $0.00203 |
| Sonnet 5 | $0.00022 | $0.00081 |
| Haiku 4.5 | $0.00011 | $0.00041 |
Grade A, and why
product-brief scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 10d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
What it actually says
Product Brief Skill
Runs at Phase 4.1 of WIZARD.md.
Use after BP v0.0.2 is accepted and a prototype direction has been approved in Phase 3.
Create docs/product/PRODUCT-BRIEF.md as the operational product document. Not investor copy — that is the Business Plan's job.
Method: reverse engineering, not invention
The product was designed in Phase 3. This skill reads docs/product/DESIGN-DIRECTION.md and prototype-lab/<chosen>/ and writes down what is already there.
Required checks:
- Every screen in the approved prototype appears in the brief, or is explicitly marked as cut.
- The user flow section matches the flow that was actually clickable in the prototype.
- UX tone is derived from
DESIGN-DIRECTION.md, not invented. - Anything the prototype implied but never showed — empty states, errors, permissions, offline, edge cases — is listed as a gap, not silently filled in.
That last check is the reason the prototype comes first. A written spec invents its own completeness; a prototype makes the holes visible.
Contents
One-liner, personas, jobs to be done, user flows, MVP, Phase 1, Phase 2, non-goals, activation moment, retention loop, monetization logic, trust/compliance requirements, UX tone, product risks.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 10d ago First seen · 30 lines · 109 tokens per session scan A fdd5df6c9e63
product-brief is a skill published in the GitHub repository lglucas/ai-dev-operating-system (11 stars, last pushed 1mo ago), licensed MIT. It adds 109 tokens to every session and 406 once invoked, about $0.0005 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
cn-check
Install and run the Continue CLI (cn) to execute AI agent checks on local code changes. Use when asked to "run checks", "lint with AI", "review my changes with cn", or set up Continue CI locally.
phone-harness
Control the user's phone — iPhone through the Mac's iPhone Mirroring window, or an Android over adb: open apps, tap, type, swipe, read the screen.
security-audit
Java security checklist covering OWASP Top 10, input validation, injection prevention, and secure coding. Works with Spring, Quarkus, Jakarta EE, and plain Java. Use when reviewing code security, before releases, or when user asks about vulnerabilities.
architecture-review
Analyze Java project architecture at macro level - package structure, module boundaries, dependency direction, and layering. Use when user asks "review architecture", "check structure", "package organization", or when evaluating if a codebase follows clean architecture principles.
issue-triage
Triage and categorize GitHub issues with priority labels. Use when user says "triage issues", "check issues", "review open issues", or during regular maintenance of GitHub issue backlog.
git-commit
Generate conventional commit messages for Java projects. Use when user says "commit", "create commit", "commit changes", or after completing code changes that need to be committed.