skill-forge

skill-forge is a skill for Claude Code from bestdeejay-design/agent-skills. It costs 173 tokens per session (2,348 once invoked), scanned A, original, MIT.

A guide for designing and improving skills, which are reusable instruction sets for coding agents. It covers their required structure, usage triggers, reliability, and presentation.

In plain words
What is it for?
Use it to create a new skill, rewrite a SKILL.md file, make a skill more reliable or creative, or check one before release.
Why use it?
It helps prevent skills from being vague, hard to trigger, or inconsistent with the skill specification. It also separates required rules from optional design choices.

Skill for Claude Code

Written for Claude Code: when-to-use in frontmatter. Also seen: mentions subagents.

Good fit Use it to create a new skill, rewrite a SKILL.md file, make a skill more reliable or creative, or check one before release.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/bestdeejay-design/agent-skills/skill-forge
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 bestdeejay-design/agent-skills --skill skill-forge
Clone the repo
git clone --depth 1 https://github.com/bestdeejay-design/agent-skills

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 skill-forge

README.md
[![agentmods](https://agentmods.dev/badge/skills/bestdeejay-design/agent-skills/skill-forge.svg)](https://agentmods.dev/skills/bestdeejay-design/agent-skills/skill-forge)
Your own site
<a href="https://agentmods.dev/skills/bestdeejay-design/agent-skills/skill-forge"><img src="https://agentmods.dev/badge/skills/bestdeejay-design/agent-skills/skill-forge.svg" alt="Measured on agentmods" height="20"></a>
Per session 173 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,348 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 $0.00173 $0.02348
Opus 5 $0.00086 $0.01174
Sonnet 5 $0.00035 $0.00470
Haiku 4.5 $0.00017 $0.00235

Measured 7d ago against content hash 2332addb0844, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

skill-forge 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 7d ago.

The scan reads SKILL.md. This mod also ships 1 executable file (scripts/forge_from_feedback.py), listed below but not scanned — reading those needs a real analyzer, not pattern matching.

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/skill-forge/SKILL.md · 152 lines

How it starts

The opening of the file, as written. The whole thing — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.

skill-forge

A compass, not a dictator. This skill helps you design skills that are maximally technological (engineered, reliable, composable), creative (generative, varied, distinctive), and aesthetically disciplined (intentional, not templated). It separates the obligatory base — rules you must not break — from accents — amplifiers you choose per task.

Russian triggers: создай скил, новый скил, улучши скил, сделай скил креативнее, эстетичный скил, технологичный скил, скилл шаблонный, перепиши SKILL.md, мета-скилл, проверь скилл перед релизом.

Level 0 — Hard rules (the base, never break these)

These come from the official Agent Skills specification (agentskills.io) plus our own working gates. They are non-negotiable.

  • Frontmatter: name (≤64 chars, a-z 0-9 -, no double hyphens, MUST match the folder name) and description (≤1024 chars, MUST state what the skill does AND when to use it). Put all "when to use" info in description, never in the body. Make triggers a little "pushy" to fight undertriggering — list synonyms and casual phrasings.
  • Progressive disclosure: keep SKILL.md under 500 lines. Bundle code in scripts/ (deterministic, repetitive tasks), docs in references/ (loaded as needed; add a TOC if >300 lines), outputs in assets/. Reference files one level deep only.
  • Voice: write in the imperative. Explain the why instead of heaped MUST/ ALWAYS/NEVER — all-caps rigidity is a yellow flag. The model is smart; reason with it.
  • Principle of Lack of Surprise: no malware, no deceptive or malicious content. A skill's intent must match its description.
  • Single data contract: one spec file (e.g. deck.json) is the source of truth; every stage reads/writes it so artifacts are regenerable.
  • Mandatory gates: nothing is "done" until automated checks PASS. At minimum: structural/format validation, content QA, and — for any visual output — a real-browser or render gate. Require EVIDENCE, not assertion: the skill must show the command it ran, its output, and the exit status. Use SCOPED CLAIMS — separate failures the change caused from pre-existing ones ("3 pre-existing failures, my change introduced none"). For unattended runs, back the gate with a deterministic Stop hook or a /goal evaluator so a turn cannot end on a false "done".
  • Reproducibility: deterministic seed so the same input yields the same output on another day.
  • Anti-template baseline (our enforcement, mechanical): ≤2 typefaces, ≤4 accent roles (keep 60-30-10), WCAG contrast (text ≥4.5:1, large/non-text ≥3:1), zero raw hex outside :root (every color is a token), one mood per artifact, one idea per slide, assertion headlines (full sentence with a verb), words-per-slide budget.

Read the full file on GitHub · 152 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.

  1. 7d ago First seen · 152 lines · 173 tokens per session scan A 2332addb0844

Subscribe to this mod's changes

skill-forge is a skill published in the GitHub repository bestdeejay-design/agent-skills (5 stars, last pushed 3d ago), licensed MIT. It adds 173 tokens to every session and 2,348 once invoked, about $0.0009 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.