write-spec

write-spec is a skill for Codex from jeremylongworth-source/AgentSkills. It costs 58 tokens per session (351 once invoked), scanned A, original, MIT.

A guide for writing product requirements documents: clear descriptions of a user problem, goals, requirements, workflows, edge cases, and testable acceptance criteria.

In plain words
What is it for?
Use it to prepare feature specifications, product briefs, requirements documents, and checks that show when a feature is complete.
Why use it?
It turns scattered research, feedback, and product ideas into an implementation-ready plan while keeping evidence, assumptions, and unresolved decisions separate.

Skill for Codex

Written for Codex: agents/openai.yaml present. Also seen: mentions Codex.

Good fit Use it to prepare feature specifications, product briefs, requirements documents, and checks that show when a feature is complete.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/jeremylongworth-source/agentskills/write-spec
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 jeremylongworth-source/AgentSkills --skill write-spec
Clone the repo
git clone --depth 1 https://github.com/jeremylongworth-source/AgentSkills

Made for: Codex.

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 write-spec

README.md
[![agentmods](https://agentmods.dev/badge/skills/jeremylongworth-source/agentskills/write-spec/github.svg)](https://agentmods.dev/skills/jeremylongworth-source/agentskills/write-spec)
Your own site
<a href="https://agentmods.dev/skills/jeremylongworth-source/agentskills/write-spec"><img src="https://agentmods.dev/badge/skills/jeremylongworth-source/agentskills/write-spec/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 write-spec

Your own site · 80×15
<a href="https://agentmods.dev/skills/jeremylongworth-source/agentskills/write-spec"><img src="https://agentmods.dev/badge/skills/jeremylongworth-source/agentskills/write-spec.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 58 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 351 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 $0.00058 $0.00351
Opus 5 $0.00029 $0.00176
Sonnet 5 $0.00012 $0.00070
Haiku 4.5 $0.00006 $0.00035

Measured 8d ago against content hash 4ac5312c99a6, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

write-spec 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 8d 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/write-spec/SKILL.md · 49 lines

What it actually says

Write Spec

Core Workflow

  1. Identify the decision, user problem, target segment, product surface, and expected outcome.
  2. Summarize evidence separately from assumptions and open questions.
  3. Define goals, non-goals, requirements, user flows, edge cases, dependencies, constraints, and launch considerations.
  4. Write acceptance criteria that are observable and testable.
  5. Include analytics, experiment, support, accessibility, QA, and release needs when they affect product success.
  6. Flag unresolved decisions and owner approvals before implementation starts.

Safety Rules

  • Do not present assumptions as customer evidence.
  • Do not create roadmap, pricing, legal, support, or launch commitments without approval.
  • Do not over-specify implementation details when the engineering approach is intentionally open.
  • Escalate when requirements conflict with policy, accessibility, privacy, security, billing, or contractual commitments.

Deliverable Shape

For product specs, provide:

  • Problem and audience
  • Evidence and assumptions
  • Goals and non-goals
  • Requirements
  • User flow or workflow
  • Edge cases and constraints
  • Acceptance criteria
  • Analytics or validation plan
  • Risks, dependencies, and open questions

References

  • Read references/write-spec-checklist.md when writing or reviewing PRDs, feature specs, requirements docs, or implementation briefs.
Files

What ships with it

2 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.

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. 8d ago First seen · 49 lines · 58 tokens per session scan A 4ac5312c99a6

Subscribe to this mod's changes

write-spec is a skill published in the GitHub repository jeremylongworth-source/AgentSkills (1 stars, last pushed 9d ago), licensed MIT. It adds 58 tokens to every session and 351 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 2026-09-03.