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.
npx agentmods add instructions/nisus74/pencil-skill/agents-mdgit clone --depth 1 https://github.com/Nisus74/pencil-skillWrote 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.
[](https://agentmods.dev/instructions/nisus74/pencil-skill/agents-md)<a href="https://agentmods.dev/instructions/nisus74/pencil-skill/agents-md"><img src="https://agentmods.dev/badge/instructions/nisus74/pencil-skill/agents-md.svg" alt="Measured on agentmods" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5 | $0.03976 | $0.03976 |
| Opus 5 | $0.01988 | $0.01988 |
| Sonnet 5 | $0.00795 | $0.00795 |
| Haiku 4.5 | $0.00398 | $0.00398 |
Grade A, and why
pencil-skill AGENTS.md 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 4d 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.
How it starts
The opening of the file, as written. The whole thing — 297 lines — stays where its author put it; the contents beside it link to each section on GitHub.
pencil-dev-skill: Project Context
This is the canonical project-context file. All AI coding tools (Claude Code, OpenAI Codex,
Cursor, etc.) should read this file for project context. Platform-specific files (CLAUDE.md)
are thin pointers to this file.
Project Purpose
Unofficial community plugin. This project is not affiliated with or endorsed by the Pencil.dev team. For the Pencil editor, MCP server, and official documentation, visit pencil.dev.
This repository is a standalone, platform-agnostic AI coding skill plugin that teaches
AI coding tools how to work with pencil.dev design files (.pen format)
via the Pencil MCP server.
Core artifact: skills/pencil-design/SKILL.md, the platform-agnostic skill content.
Platform adapters: .claude-plugin/plugin.json, .cursor-plugin/plugin.json,
.codex-plugin/plugin.json, and gemini-extension.json are the minimum files required
by each platform's installer; they exist only so users on those platforms can run a
one-line install command. They are not the substance of the project.
Naming Conventions
Three names appear in this project, each scoped to a different layer:
| Name | Scope | Where it appears |
|---|---|---|
pencil-skill |
GitHub repo name | Repo URL, clone URL |
pencil-dev-skill |
Plugin package name | plugin.json, marketplace listings |
pencil-design |
Skill name | SKILL.md frontmatter, skill activation triggers |
This is intentional: the repo is the deliverable, the plugin is the package, and the skill is the capability the AI invokes.
Repository Structure
skills/pencil-design/ # The platform-agnostic core
SKILL.md # The skill: YAML frontmatter + instructions (v0.8.0)
references/ # On-demand references loaded by the skill
mcp-tools.md # Cookbook for all 9 MCP tools + composite recipes
states.md # Component states + screen-level fault states + onboarding/settings states
flows.md # Transitions between screens (modal, validation, back-stack, onboarding, settings, search)
accessibility.md # ARIA, focus order, APCA, ARIA live regions, keyboard shortcuts, WCAG 2.2
modern-patterns.md # Container queries, fluid type, AI-UI, animation timing, command palette, perceived perf
pencil-cli.md # Full Pencil CLI reference + When CLI vs MCP table
pen-schema.md # .pen file JSON schema reference (v2.14)
batch-design-grammar.md # batch_design JavaScript API (Insert/Copy/Update/Replace/Move/Delete/SetVariables/Generate/FindEmptySpace)
advanced-canvas.md # v2.14 canvas features: shader fills, mesh gradients, script nodes, ellipse arcs/donuts, prompt/context nodes
component-anatomy.md # Reading component structure: slots, descendants paths, state activation
composition-patterns.md # Compound components, slot design, variant naming, status workflow
file-architecture.md # Cover frame, section regions, hierarchical naming, multi-.pen layouts
forms.md # Submit behaviour, validation, error display, autofill, mobile inputs
interactions.md # Keyboard, focus, hit targets, loading timing, destructive actions, URL-as-state
visual-hierarchy.md # Six levers, eye-flow patterns, whitespace, density strategy
layout-patterns.md # Hero variations, feature sections beyond three-card grid, pricing, dashboards, settings, list-detail, empty pages (cited 2025/2026 exemplars)
iteration-patterns.md # Failure-mode rescues (too busy/sparse/generic/un-premium), self-critique gate, reference-image translation, three-iteration limit
microcopy.md # Voice/tone framework, action-specific CTAs, error message anatomy, empty/success/confirmation copy, loading copy, localisation
mobile-patterns.md # Safe areas, sheets vs modals, sheet detents, gestures, haptics, tab bars, native conventions per platform
iconography.md # Stroke weight, sizing, semantic icons, accessibility (aria-hidden vs accessible name), family consistency
performance-design.md # Network budgets, Core Web Vitals (LCP/CLS/INP), virtualisation, image and font optimisation, theme-color
industry-patterns.md # 8 industry families with 15-20 rules each + completeness pressure tests for SaaS / Website / Mobile
data-viz.md # 25-chart selection matrix, colour-blind palettes (Okabe-Ito, ColorBrewer, Viridis), dashboard tiles, anti-patterns
style-catalogue.md # 30+ named UI styles (menu) organised by family with mood, when-to-use, anti-pattern, exemplars
colour-palettes.md # 40+ palette recipes (menu) tagged by industry/mood; recipes point to Tailwind/Radix/IBM Carbon/Material 3/Apple HIG
font-pairings.md # 30+ typography pairings (menu); recipes point to Google Fonts/Vercel/GitHub/commercial foundries
codex-tools.md # OpenAI Codex tool name mappings
design-system/ # Optional design-system reference templates (one level deep)
README.md # Agent loading guide
CUSTOMISING.md # Plain-English guide for non-technical editors
accessibility.md # Project a11y standards (WCAG/APCA, keyboard, screen reader)
empty-states.md # Per-surface empty state catalogue with copy templates
file-architecture.md # Project .pen file structure and naming conventions
forms.md # Form conventions (validation, error display, save patterns)
micro-interactions.md # Per-interaction motion specs
navigation.md # Primary nav patterns, workspace switcher, mobile tab bar
onboarding.md # First-run experience (sample-data vs blank slate)
search.md # Search shape (instant / submit / hybrid), filters, URL state
visual-style.md # Project's chosen style identity (style + palette + font picks)
examples/ # 15 worked examples with real MCP tool sequences (one level deep)
example-login-screen.md # Greenfield auth screen
example-import-library.md # Import .lib.pen library + instantiate components
example-error-screen.md # 404 + offline page pair
example-form-flow.md # Multi-step signup with email verification
example-component-deep-dive.md # Full read→understand→instantiate cycle
example-style-selection.md # Catalogue (style + palette + fonts) → SetVariables → tokens commit → starter components
example-settings-page.md # Settings with sidebar nav, autosave + explicit-save for high-stakes
example-dashboard.md # KPI cards + chart tile + recent-activity table
example-marketing-page.md # Marketing page avoiding three-card grid (asymmetric hero, bento features)
example-mobile-app.md # Mobile app with bottom tab bar, sheet detents, safe areas, haptics
example-data-visualization.md # Multi-chart dashboard with colour-blind-safe palettes
example-onboarding-flow.md # Three-step onboarding with progress, skip, sample-data routing
example-component-variants.md # Complete Button family with all variants and states
example-pricing-table.md # Three-tier pricing with highlighted recommended tier
example-file-cover-and-sections.md # .pen file with Cover frame, section regions, hierarchical naming
# Platform install adapters (required by each platform's installer)
.claude-plugin/plugin.json # Claude Code plugin manifest
.claude-plugin/marketplace.json # Claude Code marketplace listing (single-plugin marketplace)
.cursor-plugin/plugin.json # Cursor plugin manifest (Cursor 2.5+)
.codex-plugin/plugin.json # OpenAI Codex plugin manifest
gemini-extension.json # Gemini CLI extension manifest
# Project context files
AGENTS.md # This file — canonical, platform-agnostic
CLAUDE.md # Thin pointer to AGENTS.md (for Claude Code)
HARNESSES.md # Cross-platform skill capability matrix (frontmatter, directories, substitution)
# Public-facing
README.md
LICENSE
# Repo hygiene
.gitignore # Includes secret patterns
.gitattributes # Cross-platform line-ending normalization
.gitleaks.toml # Secret-scanning config
# Quality tooling
tools/
skill-lint.py # OWASP Agentic Skills Top 10 lint (CI + pre-commit)
test_skill_lint.py # 40 unit tests for skill-lint
requirements.txt # pip deps for Dependabot
# Documentation
SECURITY.md # Security policy + OWASP AST compliance map (repo root)
docs/
CONTRIBUTING.md
CODE_OF_CONDUCT.md
CHANGELOG.md
# GitHub repo configuration
.github/
PULL_REQUEST_TEMPLATE.md
ISSUE_TEMPLATE/
CODEOWNERS
dependabot.yml
workflows/
secret-scan.yml # gitleaks on push + PR
skill-lint.yml # skill-lint + unit tests on push + PR
.pre-commit-config.yaml # Local gate: skill-lint + gitleaks + hygiene
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.
- 4d ago First seen · 297 lines · 3,976 tokens per session scan A 085ac995b2ae
pencil-skill AGENTS.md is an instructions file published in the GitHub repository Nisus74/pencil-skill (22 stars, last pushed 1mo ago), licensed MIT. It adds 3,976 tokens to every session, about $0.0199 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 2026-08-30.
Other instructions, from other repositories
taste-skill copilot-instructions.md
Instructions for Leonxlnx/taste-skill, covering copilot instructions: taste standard and the "anti-slop" manifesto for copilot.
visual-stack CLAUDE.md
Claude Code instructions for Cavalry-Collective/visual-stack, covering claude.md, what this is, commands, architecture and contracts / engine / adapters / profiles.
ux-expert-skills AGENTS.md
Instructions for guofu-shiqu/ux-expert-skills, covering agents.md — codex agent instructions, role, capabilities, skill catalog and workflow.
solidworks-api-skill CLAUDE.md
Instructions for guoleizhen717/solidworks-api-skill, covering solidworks api skill repository, repository purpose, skill scope and project conventions.
devourer AGENTS.md
AGENTS.md instructions for LoserLab/devourer, covering devourer, when to suggest this skill, what it produces, key files and suite context.
pencil-atelier CLAUDE.md
Claude Code instructions for JesusJimenezC/pencil-atelier, covering claude.md, repository purpose, plugin surface, architectural invariants and the scale is the product.