Skill Forge

Use before creating or editing any Agent Skill or any file bundled with one: a SKILL.md, a skill's description or frontmatter, its…

Context cost
23.8k tokensestimated from the bundle, loaded when it triggers
Bundle
12 files · 108.6 kB2 scripts among them — read before you run
Licence
not declarednone named by its author
Last change
—v2.8.1
Servers it uses
Noneruns standalone

What it does

Use before creating or editing any Agent Skill or any file bundled with one: a SKILL.md, a skill's description or frontmatter, its AGENTS.md or README, or a reference, script, asset, or other file under a skill directory. Load it before the first edit, not after. Also use when designing, refining, reviewing, or validating a skill that follows the open SKILL.md standard: writing or tuning its triggering description, organizing its references, scripts, or assets directories, preserving key wording and meaning during edits, deciding automatic or manual invocation, or answering questions about…

What this skill changes about the agent has not been set out here as a list. Its SKILL.md, shown below, says it in the author’s own words.

agentproductivity

The skill itself

A skill is instructions the model reads, so you can see what you are getting: below is the start of its SKILL.md. The front matter loads with every session, the body loads when the skill triggers, and the whole file comes with the install.

SKILL.md23.8 kB · preview
--- name: "skill-forge" compatibility: "The bundled validator requires Node.js 18 or later. Its remote route also requires npm and network access when uncached." metadata: author: "Leeor Nahum" version: "2.8.1" ---
10# Skill Forge
11
12Create skills that are concise, precisely scoped, and free of context bloat. A skill transfers knowledge the agent lacks, not knowledge it already has.
13
14The upstream source of truth is [agentskills.io](https://agentskills.io/specification). The specification and its authoring guides are vendored under references/. This file is the opinionated distillation. The references are the upstream originals, and AGENTS.md owns how they are kept current.
15
16## Reference Loading
17
18- Read the [Agent Skills specification](references/specification.md) before creating a skill from scratch, and whenever unsure about an exact frontmatter constraint, the directory contract, or what the standard requires versus what is host-specific or house convention. It is the normative spec. Follow it exactly.
19- Read [Optimizing descriptions](references/optimizing-descriptions.md) when a skill misfires or fails to trigger and the description needs systematic tuning, or when running a trigger evaluation.
20- Read [Using scripts](references/using-scripts.md) when adding or reviewing a scripts/ directory.
21- Read [Evaluating skills](references/evaluating-skills.md) when building evals for a skill or measuring with-skill versus without-skill performance.
22- Read [Skill authoring best practices](references/best-practices.md) when structuring a complex multi-file skill and this file's rules leave a judgment call open.
23
24Where a reference conflicts with this file on house style, this file wins. The specification still wins on the format contract.
25
26## What Each Part Is For
27
28Agents routinely blur these boundaries. Check every skill edit against this table:
This is a preview of SKILL.md. Download or install the skill to get the whole thing.
In the file
SKILL.md3,644 words
Files12
Licencenot declared
Why you can read it

Nothing in a skill executes. The client loads the text and the model follows it, so a skill can be audited the way a runbook is — by reading it.

What it costs in context

Skills are not billed by the call. They are paid for in context: every token the instructions occupy is a token your code, your diff and your conversation cannot use. Here is what this one takes and when it takes it.

≈240
always loaded
The name and description, so the model knows the skill exists and when to reach for it.
23,510
on trigger
The instruction body and 11 supporting files, read only when the skill fires.
11.9%
of a 200k window
Ten skills this size would not fit in the window together.
050k100k150k200k context window

23.8k tokens, estimated from the bundle at four bytes to the token, held for the rest of the session once it triggers. Heavy. Teams tend to install this one per project rather than globally, and load it only when the job comes up.

Servers bill, skills cost

A server charges by the month. A skill charges once per session, in context, and then keeps charging it for as long as the session lives.

Before and after

The same question, put to the same model twice: once as it comes, and once with these instructions loaded.

No worked example has been published for this skill yet.

The procedure it runs

The procedure has not been set out here step by step. It is in the body of its SKILL.md: the start of it is shown above, and the whole file comes with the install.

Prose, not code

These steps are written for a model to follow, not executed by a runtime. It can still be told to skip one, and it will say so when it does.

Servers it uses

None. This skill calls no MCP servers at all.

Everything it needs is in the instructions, so it works in a project with nothing connected — the model reads the file and changes how it works with what it can already reach.

Its SKILL.md does not declare which tools it asks the agent for, so what it touches is whatever the instructions themselves ask for — read them before you install it.

What it asks for
Writes filesnot declared
Network accessnot declared

This SKILL.md carries no allowed-tools line, so neither is declared. A skill grants no permissions of its own — it can only ask for tools your client already has.

What it will not do

Every skill is narrow, and the useful ones say where they stop. These are the jobs this one is the wrong tool for.

What this skill is not for has not been published here. Nothing is implied by that: it is a section the author has not filled in.

What is in the bundle

12 files, 108.6 kB on disk. Mostly text — the instructions the model reads — with 2 scripts in it that your client would run only if the instructions tell it to. 1 file of its source is not in the download — listed after these, with why.

  • SKILL.md23.8 kB
  • AGENTS.md4.5 kB
  • package.json0.3 kB
  • README.md1.1 kB
  • references/best-practices.md14.7 kB
  • references/evaluating-skills.md16.9 kB
  • references/optimizing-descriptions.md13.3 kB
  • references/specification.md7.2 kB
  • references/using-scripts.md12.2 kB
  • scripts/sync.mjs3.9 kB
  • scripts/validate.mjs9.7 kB
  • .github/workflows/sync-upstream.yml1.0 kB

Not in the download

Not carried is a type a skill download does not hold. Take it from its source.

  • .gitattributesnot carried
What is not in it

A skill installs nothing and depends on nothing: it is a folder your client reads. This one carries 2 scripts beside the text, so the download is 12 files — not the whole of its source: 1 file is left out. It is listed under the files, with why.

Install

Installing copies the bundle into your project. Nothing runs at install time — the files sit on disk until the model reads them.

# Skill Forge · 23.8k tokens when loaded · macOS, Linux mkdir -p .claude/skills && t=$(mktemp -d) && curl -fsSL -o "$t/bundle.tar.gz" https://mcprush.com/api/skills/leeornahum-skill-forge/bundle.tar.gz && tar -xzf "$t/bundle.tar.gz" -C "$t" && [ -d "$t/skill-forge" ] && { [ ! -e .claude/skills/skill-forge ] || { mv .claude/skills/skill-forge "$t/.previous" && echo "Previous copy moved to $t/.previous"; }; } && mv "$t/skill-forge" .claude/skills/ && echo "Installed .claude/skills/skill-forge"
On Windows, or any OS with Node 20+
npx mcprush@latest skill add leeornahum/skill-forge

Windows PowerShell says 'running scripts is disabled on this system'? Run Set-ExecutionPolicy -Scope CurrentUser RemoteSigned once, or type npx.cmd instead of npx (codex.cmd, gemini.cmd, grok.cmd likewise). PowerShell 7 needs neither. Writes to .claude/skills/skill-forge/ in the current project. For every project instead, run mkdir -p ~/.claude/skills && t=$(mktemp -d) && curl -fsSL -o "$t/bundle.tar.gz" https://mcprush.com/api/skills/leeornahum-skill-forge/bundle.tar.gz && tar -xzf "$t/bundle.tar.gz" -C "$t" && [ -d "$t/skill-forge" ] && { [ ! -e ~/.claude/skills/skill-forge ] || { mv ~/.claude/skills/skill-forge "$t/.previous" && echo "Previous copy moved to $t/.previous"; }; } && mv "$t/skill-forge" ~/.claude/skills/ && echo "Installed ~/.claude/skills/skill-forge" (macOS, Linux) — or add --global to the npx line. The curl line replaces .claude/skills/skill-forge/ only after the download succeeds, so files left there by another skill of the same name, or by an older release, do not mix in. A copy already there is moved aside, not deleted, and the line prints where. Not in this download: 1 file of its source (which one, and why). Take it from its source.

Which clients pick it up on their own

A skill is a folder of text. Most of these read a skills folder and pick it up without being told; the rest take the same folder another way — an upload in the app, a parameter on an API call — and then choose it by its description just the same.

Claude Code.claude/skills/
Claude DesktopCustomize › Skills
ChatGPTSkills › Create › Upload
Cursor.cursor/skills/
VS Code.github/skills/
Codex CLI.agents/skills/
Gemini CLI.gemini/skills/
Grok Build.grok/skills/
Microsoft CopilotSkills › Upload a skill
PerplexityComputer › Skills › Upload a skill
DeepSeek Harness.dsh/skills/
Zed.agents/skills/
Devin Desktop.devin/skills/
Windsurf (legacy).windsurf/skills/
OpenAI Agents SDKInstructions or sandbox Skills
HTTP / APIa request parameter
This release
Version2.8.1
Publishedno release date on file
PriceFree
Referenceleeornahum/skill-forge

Versions

v2.8.1 is what is on the shelf; no release here carries a date. Instructions change more often than APIs do — a skill can be rewritten entirely without anything it depends on moving.

v2.8.1
  • No earlier releases have been published to the marketplace.
Pinning

The install command always fetches the release that is current the day you run it — v2.8.1 today — and cannot ask for an earlier one. The copy on your disk does not change until you run it again.

Reviews

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