prd-writing

prd-writing is a skill for Claude Code from assimovt/productskills. It costs 50 tokens per session (773 once invoked), scanned A, original, MIT.

A product requirements document (PRD) writing guide for turning customer evidence and product decisions into a short, structured specification.

In plain words
What is it for?
Use it to write PRDs, feature specifications, and product requirements with defined problems, target users, priorities, and measurable goals.
Why use it?
It helps prevent vague requirements, uncontrolled scope, and success measures that cannot be checked. It also makes the document easier for engineers to read and follow.

Skill for Claude Code

Written for Claude Code: shipped in a Claude Code plugin.

Part of the product-skills plugin — 16 skills shipped together

Good fit Use it to write PRDs, feature specifications, and product requirements with defined problems, target users, priorities, and measurable goals.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/assimovt/productskills/prd-writing
Install

Getting it into your agent

One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.

Any agent
npx skills add assimovt/productskills --skill prd-writing
Clone the repo
git clone --depth 1 https://github.com/assimovt/productskills

Made for: Claude Code.

Or install product-skills, the plugin that ships this one along with the rest of its 16 skills.

Wrote 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.

agentmods badge for prd-writing

README.md
[![agentmods](https://agentmods.dev/badge/skills/assimovt/productskills/prd-writing/github.svg)](https://agentmods.dev/skills/assimovt/productskills/prd-writing)
Your own site
<a href="https://agentmods.dev/skills/assimovt/productskills/prd-writing"><img src="https://agentmods.dev/badge/skills/assimovt/productskills/prd-writing/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.

agentmods 80×15 button for prd-writing

Your own site · 80×15
<a href="https://agentmods.dev/skills/assimovt/productskills/prd-writing"><img src="https://agentmods.dev/badge/skills/assimovt/productskills/prd-writing.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 773 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5.1 $0.00050 $0.00773
Opus 5 $0.00025 $0.00387
Sonnet 5 $0.00010 $0.00155
Haiku 4.5 $0.00005 $0.00077

Measured 11d ago against content hash 3c4e46938207, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

prd-writing 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 11d 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.

skills/prd-writing/SKILL.md · 77 lines

How it starts

The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Write PRDs that are evidence-first, concise, and scannable. A PRD is a thinking tool — if it's longer than 1200 words, the author hasn't thought hard enough. Brief specs are more likely to be read, more likely to be followed, and more likely to ship on time.

Structure

Follow this structure. Every section is mandatory unless marked optional.

1. Problem

Lead with customer evidence. Quotes, data, support tickets, observed behavior. If you have no evidence, say so explicitly — that's an opinion-driven PRD and should be flagged.

Example:

"3 of 5 interviewed customers abandon onboarding at the team invite step. Average time spent: 47 seconds before closing the tab."

NOT: "Users find onboarding confusing."

2. Goals

Measurable outcomes, not outputs. Each goal has a number attached.

  • "Reduce onboarding drop-off from 60% to under 30%"
  • NOT "Improve the onboarding experience"

3. Target Users

Who specifically benefits. Be narrow. "Series A startup founders doing PM work before their first PM hire" — not "product managers."

4. Requirements

Use P0/P1/P2 with clear definitions:

  • P0 — Does not ship without it. The feature is broken or useless without this.
  • P1 — Ships without it, but significantly degraded. Do in same cycle if possible.
  • P2 — Nice to have. Candidate for fast follow.

Each requirement is one sentence. If a requirement needs a paragraph to explain, it's too big — break it down.

5. Success Metrics

Numbers. Always numbers. "Reduce X from Y to Z within W weeks."

ALWAYS pair each metric with a counter-metric to prevent gaming:

  • Metric: "Increase activation rate to 70%"
  • Counter-metric: "Without decreasing 30-day retention below 45%"

6. Out of Scope

What you are deliberately NOT building and why. This section prevents scope creep and signals that you've thought about boundaries.

7. Open Questions (optional)

Unresolved decisions that need input. Each question names who should answer it and by when.

Guidelines

Read the full file on GitHub · 77 lines

Changes

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.

  1. 11d ago First seen · 77 lines · 50 tokens per session scan A 3c4e46938207

Subscribe to this mod's changes

prd-writing is a skill published in the GitHub repository assimovt/productskills (68 stars, last pushed 6mo ago), licensed MIT. It adds 50 tokens to every session and 773 once invoked, about $0.0003 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.

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