skill-authoring

skill-authoring is a skill for Claude Code, Codex from int2t05/engineering-skills. It costs 118 tokens per session (1,973 once invoked), scanned A, original, MIT.

Skill-writing workflow for creating, editing, or evaluating add-on instructions in this collection. It covers the required document structure, trigger wording, adapter generation, and validation.

In plain words
What is it for?
Use it to create a new skill, revise an existing one, test whether its triggers are distinct, or validate its files.
Why use it?
It helps keep skills consistent and makes their activation rules less likely to be missed or triggered for the wrong work.

Skill for Claude CodeCodex

Written for Claude Code and Codex: ${CLAUDE_PLUGIN_ROOT} variable, but also agents/openai.yaml present. Also seen: mentions AGENTS.md; mentions Codex.

Runs only inside its plugin — its command needs a path that Claude Code sets for a plugin’s own hooks and for nothing else. Install the plugin, not this.

Part of the engineering-skills plugin — 47 skills, 1 hook shipped together

Good fit Use it to create a new skill, revise an existing one, test…

Compare 6 skills from other repositories ↓
Install

Getting it into your agent

This one installs as part of its plugin. Adding the marketplace and installing the plugin brings it with everything else the plugin ships.

Claude Code
/plugin marketplace add int2t05/engineering-skills
Claude Code
/plugin install engineering-skills

Made for: Claude Code, Codex.

Or install engineering-skills, the plugin that ships this one along with the rest of its 47 skills, 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.

agentmods badge for skill-authoring

README.md
[![agentmods](https://agentmods.dev/badge/skills/int2t05/engineering-skills/skill-authoring.svg)](https://agentmods.dev/skills/int2t05/engineering-skills/skill-authoring)
Your own site
<a href="https://agentmods.dev/skills/int2t05/engineering-skills/skill-authoring"><img src="https://agentmods.dev/badge/skills/int2t05/engineering-skills/skill-authoring.svg" alt="Measured on agentmods" height="20"></a>
Per session 118 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,973 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 $0.00118 $0.01973
Opus 5 $0.00059 $0.00986
Sonnet 5 $0.00024 $0.00395
Haiku 4.5 $0.00012 $0.00197

Measured 6d ago against content hash a50cac6c9f89, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

skill-authoring 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 6d 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/meta/skill-authoring/SKILL.md · 94 lines

How it starts

The opening of the file, as written. The whole thing — 94 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Skill Authoring

Create, edit, and evaluate skills in this collection. Every skill conforms to the anatomy in references/skill-anatomy.md and passes scripts/validate-skills.sh. This skill is the authoring half — using-skills routes work to existing skills; this one makes new ones or fixes existing ones.

When to use

  • Creating a new skill (new SDLC phase gap, repeated task worth a skill)
  • Editing an existing skill's frontmatter, steps, or references
  • Tuning a skill's description triggers (false positives, false negatives, collision with another skill)
  • Evaluating a skill — does it fire when it should, stay distinct from neighbors, change agent behavior?
  • Triggers on "write a skill", "edit skill", "skill eval", "tune triggers", "写技能", "改技能", "技能评估"

Not for: routing a task to an existing skill (use using-skills); designing an MCP server (out of scope, see official mcp-builder docs); writing project docs like PRD/README (use spec/oss-polish).

Steps

1. Check the anatomy before writing

Load ${CLAUDE_PLUGIN_ROOT}/references/skill-anatomy.md — the folder layout, frontmatter rules (name + description + optional disable-model-invocation only), the four body sections (When to use / Steps / Verify / References), the **Output:** convention, progressive disclosure (15-150 line SKILL.md, depth in references/), and the description hybrid format (Use when… + Triggers on… + exclusions, ≤1024 chars, no cross-skill phrase collisions).

2. Place the skill and wire the backbone

  • Phase — pick the phase by output type + consumer, not by method. A skill producing a design artifact for design consumers goes in 03-design even if it reuses research methods (see design-research). Method does not set phase; output and consumers do.
  • Backbone — every skill links engineering-principles.md. PM-side skills also link product-principles.md; UIUX skills also link design-principles.md. The validator enforces these (see scripts/validate-skills.sh pm_skills/uiux_skills lists — add the new skill there if it's PM or UIUX).
  • Pathskills/<phase>/<name>/SKILL.md (kebab-case name, uppercase SKILL.md).

Read the full file on GitHub · 94 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. 6d ago First seen · 94 lines · 118 tokens per session scan A a50cac6c9f89

Subscribe to this mod's changes

skill-authoring is a skill published in the GitHub repository int2t05/engineering-skills (3 stars, last pushed 6d ago), licensed MIT. It adds 118 tokens to every session and 1,973 once invoked, about $0.0006 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.

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