A workflow for writing or revising a feature specification before implementation. A specification describes what a feature should do and why, while later design work decides how to build it.

Use it to define a new feature, revise an existing feature’s requirements, and prepare work that spans sessions or people.

Starting with an idea or task list can leave requirements ambiguous and make the result hard to check. This turns the idea into ordered user stories and independently testable acceptance criteria.

specify — Skill for Claude Code by mehrad-dm/mastermind

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 mehrad-dm/mastermind --skill specify

Clone the repo

git clone --depth 1 https://github.com/mehrad-dm/mastermind

Made for: Claude Code.

Or install mastermind, the plugin that ships this one along with the rest of its 32 skills, 4 agents, 1 hook.

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.

README.md

[![agentmods](https://agentmods.dev/badge/skills/mehrad-dm/mastermind/specify/github.svg)](https://agentmods.dev/skills/mehrad-dm/mastermind/specify)

Your own site

<a href="https://agentmods.dev/skills/mehrad-dm/mastermind/specify"><img src="https://agentmods.dev/badge/skills/mehrad-dm/mastermind/specify/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.

Your own site · 80×15

<a href="https://agentmods.dev/skills/mehrad-dm/mastermind/specify"><img src="https://agentmods.dev/badge/skills/mehrad-dm/mastermind/specify.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session 108 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.

When invoked 1,136 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.

Model	Per session	Once invoked
Fable 5.1	$0.00108	$0.01136
Opus 5.5	$0.00043	$0.00454
Sonnet 5.5	$0.00022	$0.00227
Haiku 4.5	$0.00011	$0.00114

Measured 15d ago against content hash 5c6a032270b9, method: parsed. Prices are Anthropic first-party input rates as of 2026-10-07, from the pricing page.

Security

Grade A, and why

specify 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 15d 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/specify/SKILL.md · 74 lines

How it starts

The opening of the file, as written. The whole thing — 74 lines — stays where its author put it; the contents beside it link to each section on GitHub.

MasterMind: Specify

The spec says what and why, for a reader who does not code. The how comes later, in blueprint. Read ~/.mastermind/engineering/core/spec-driven.md for the layout, IDs and lifecycle. Feature: $ARGUMENTS.

Write it

Open the folder. Pick the next number in specs/ and a two-to-four word name: specs/012-csv-export/. Revising an existing spec? Work in that folder instead. Search specs/ and the code for the concept first: a feature that already exists is amended, never specified twice.
Start from the template. specs/.templates/spec.md if present, else template.md.
Read what bounds it. specs/constitution.md, specs/product.md, the brief's glossary, and any earlier spec this one amends.
Write user stories in priority order. P1 alone is a usable product. Each story carries an independent test: how someone would see it working with no lower-priority story built. A story may rely on a higher-priority one; its test then assumes only those.
Write acceptance criteria with their trigger inside, numbered per story (US1/AC1), in the four shapes interview uses: When, While, If ... then, Where.
Write functional requirements (FR-001), each testable alone, and success criteria (SC-001), each measurable from the user's side with no technology named.
Fill the rest. Key entities (no fields or types yet), edge cases, out of scope, and assumptions.
Name things once. Add each new domain word to the glossary in .mastermind/brief.md, creating the file or the section if it is missing, and use those exact words in the spec.

Gaps: guess well, mark the few that matter

Fill a gap with the reasonable default for this kind of product and record it under Assumptions. Mark a gap [NEEDS CLARIFICATION: <question>] only when all three hold: it changes scope, security or the user's experience; two readings lead to different products; and no default is reasonable.

Read the full file on GitHub · 74 lines

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.

15d ago First seen · 74 lines · 108 tokens per session scan A 5c6a032270b9

Subscribe to this mod's changes

specify is a skill published in the GitHub repository mehrad-dm/mastermind (23 stars, last pushed 6d ago), licensed MIT. It adds 108 tokens to every session and 1,136 once invoked, about $0.0004 per session on Opus 5.5. 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 2026-10-08.

Claude Code Planning Project management ai ai-agents claude codex coding-assistant

st-execute-blueprint

Use when the user asks to run, execute, implement, or carry out a Strikethroo plan or its blueprint by plan ID in this repository — triggers include execute blueprint, run the plan, implement plan, build the plan. Do not use to create a plan, to only generate tasks, to run a single task, or for generic development…

e0ipso/strikethroo · 82 tokens

st-generate-tasks

Use when the user asks to decompose, break down, or generate tasks for an existing Strikethroo plan ID in this repository — triggers include generate tasks, break down the plan, decompose plan, create the task blueprint. Do not use to create a new plan, to execute tasks, or for generic project planning outside…

e0ipso/strikethroo · 77 tokens

st-create-plan

Use when the user asks to draft, scope, or write up a new Strikethroo plan for a work order, feature, or initiative in this repository — triggers include create plan, new plan, plan this, scope a plan, strikethroo plan. Do not use to decompose an existing plan into tasks, to execute a plan, or for generic…

e0ipso/strikethroo · 85 tokens

specify