What is plugin-and-skill-dev?

Guidelines for writing stable, maintainable skills, agents, and commands for coding assistants. They cover structure, sequencing, and protecting personal information in examples.

Use it when creating, editing, or reviewing instruction files for skills, agents, or commands.

They reduce ambiguity and privacy mistakes in the instructions that control automated coding tools.

plugin-and-skill-dev — Plugin for Claude Code by motlin

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.

Clone the repo

git clone --depth 1 https://github.com/motlin/claude-code-plugins

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.

README.md

[![agentmods](https://agentmods.dev/badge/plugins/motlin/claude-code-plugins/plugin-and-skill-dev/github.svg)](https://agentmods.dev/plugins/motlin/claude-code-plugins/plugin-and-skill-dev)

Your own site

<a href="https://agentmods.dev/plugins/motlin/claude-code-plugins/plugin-and-skill-dev"><img src="https://agentmods.dev/badge/plugins/motlin/claude-code-plugins/plugin-and-skill-dev/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/plugins/motlin/claude-code-plugins/plugin-and-skill-dev"><img src="https://agentmods.dev/badge/plugins/motlin/claude-code-plugins/plugin-and-skill-dev.svg" alt="Reviewed on agentmods" width="80" height="20"></a>

Per session not measured What this adds to a session before it is invoked.

When invoked not measured The manifest loads nothing itself; its 1 skill cost 80 tokens a session between them.

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.

Security

Grade A, and why

plugin-and-skill-dev 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 3d 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.

plugins/plugin-and-skill-dev/.claude-plugin/plugin.json · 12 lines

What it actually says

{
	"$schema": "https://anthropic.com/claude-code/plugin.schema.json",
	"name": "plugin-and-skill-dev",
	"description": "Development guidelines for writing stable, maintainable skills, agents, and commands",
	"version": "1.37.0",
	"license": "Apache-2.0",
	"author": {
		"name": "Craig Motlin"
	},
	"skills": ["./skills/writing-instructions"]
}

Contents

What it installs

The manifest is a name and a version. 1 skill travel with it, and installing the plugin installs all of them — 80 tokens a session between them. Each is measured on its own page, and each can be installed alone.

Skill writing-instructions A 80 tokens

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.

3d ago Changed 745f11fbf86c
6d ago Changed 7e67c67b9dba
9d ago Changed a6e641dd9d2b
29d ago Changed a508260944bd
1mo ago Changed 46ca3108701f
1mo ago Changed b1fb29fda085
1mo ago Changed f368d986cafd
1mo ago Changed 99b217df3463
1mo ago First seen · 12 lines scan A f33c35b66db0

Subscribe to this mod's changes

plugin-and-skill-dev is a plugin published in the GitHub repository motlin/claude-code-plugins (20 stars, last pushed yesterday), licensed Apache-2.0. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-09-04.

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