feature-spec

feature-spec is a skill for Claude Code from ArtemioPadilla/agent-triforce. It costs 33 tokens per session (510 once invoked), scanned A, original, MIT.

A workflow for writing a structured specification for a new product feature. It covers user stories, dependencies, acceptance criteria, and different levels of detail.

In plain words
What is it for?
Use it when defining a bug fix, small enhancement, standard feature, or large multi-phase feature, with the result saved in docs/specs/.
Why use it?
It turns a feature idea into a shared plan that developers can estimate, build, and test. It also helps reveal missing decisions before implementation starts.

Skill for Claude Code

Written for Claude Code: context: fork in frontmatter. Also seen: agent in frontmatter.

Good fit Use it when defining a bug fix, small enhancement, standard feature, or large multi-phase feature, with the result saved in docs/specs/.

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Install with agentmods
npx agentmods add skills/artemiopadilla/agent-triforce/feature-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 ArtemioPadilla/agent-triforce --skill feature-spec
Clone the repo
git clone --depth 1 https://github.com/ArtemioPadilla/agent-triforce

Made for: Claude Code.

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 feature-spec

README.md
[![agentmods](https://agentmods.dev/badge/skills/artemiopadilla/agent-triforce/feature-spec/github.svg)](https://agentmods.dev/skills/artemiopadilla/agent-triforce/feature-spec)
Your own site
<a href="https://agentmods.dev/skills/artemiopadilla/agent-triforce/feature-spec"><img src="https://agentmods.dev/badge/skills/artemiopadilla/agent-triforce/feature-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 feature-spec

Your own site · 80×15
<a href="https://agentmods.dev/skills/artemiopadilla/agent-triforce/feature-spec"><img src="https://agentmods.dev/badge/skills/artemiopadilla/agent-triforce/feature-spec.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 33 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 510 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 $0.00033 $0.00510
Opus 5 $0.00016 $0.00255
Sonnet 5 $0.00007 $0.00102
Haiku 4.5 $0.00003 $0.00051

Measured 11d ago against content hash f8c0eeb94f31, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

feature-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 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.

.claude/skills/feature-spec/SKILL.md · 48 lines

What it actually says

Create a feature specification for: $ARGUMENTS

Follow these steps:

SIGN IN:

  • Run the SIGN IN checklist from your agent file
  • Surface any initial concerns about this feature request

TIER SELECTION:

  1. Ask the user which spec tier to use:
    • S (Small): Bug fix, tweak, minor enhancement (~10 min)
    • M (Medium): Standard feature — default choice (~30-60 min)
    • L (Large): Epic, multi-phase, API-heavy (~60-90 min)
  2. If the user does not specify, default to M

RESEARCH (READ-DO): 3. Read existing specs in docs/specs/ to understand current patterns and avoid conflicts 4. Identify dependencies on existing features or systems

BUILD: 5. Create the spec at docs/specs/{feature-name}.md using the tier-appropriate template from your system prompt 6. For each user story, validate against INVEST:

  • Independent: can be delivered separately
  • Negotiable: not a rigid contract, allows discussion
  • Valuable: delivers value to user or business
  • Estimable: Dev can estimate effort
  • Small: fits in one iteration
  • Testable: has clear acceptance criteria
  1. For M/L tiers, verify IEEE 830 quality attributes: completeness, consistency, unambiguity, verifiability
  2. For M/L tiers, fill in testing considerations: identify the 2-3 highest-risk acceptance criteria, recommend a test design technique for each (BVA for bounded inputs, EP for categorical inputs, Decision Table for complex branching, State Transition for lifecycle objects), note test data needs, and flag non-functional test requirements

TIME OUT -- Run Spec Completion Checklist (DO-CONFIRM): 8. Run through every item in the Spec Completion checklist from your agent file 9. Fix any gaps BEFORE proceeding

SIGN OUT: 10. Write the Handoff-to-Forja using the communication checklist 11. Run the SIGN OUT checklist from your agent file

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 · 48 lines · 33 tokens per session scan A f8c0eeb94f31

Subscribe to this mod's changes

feature-spec is a skill published in the GitHub repository ArtemioPadilla/agent-triforce (3 stars, last pushed 4mo ago), licensed MIT. It adds 33 tokens to every session and 510 once invoked, about $0.0002 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 2026-08-31.