Agent Skills guides

• What is a Claude skill?

  The definition, how skills load in three tiers, and how they differ from prompts and MCP servers.

• Skills vs subagents vs MCP vs plugins

  The four Claude Code primitives separated, with a comparison table and decision tree.

• Skill vs MCP vs Plugin

  The shorter three-way primer for when you do not need subagents in the picture.

• How to install a skill

  The install command for each agent — Claude Code, Cursor, Codex, Gemini CLI, Antigravity.

• How to create a skill

  Write your own SKILL.md — folder, trigger-rich description, instructions, and a copy-paste template.

• Anatomy of a SKILL.md

  The frontmatter fields, when to add scripts, and the description pattern that makes a skill trigger.

• Best Claude Code & agent Skills, by use case

  The best verified SKILL.md agent Skills for each developer job — code review, security, testing, DevOps, frontend, SEO, marketing, data analysis, document processing, web scraping, databases, email, diagrams, and workflow orchestration — with the top pick per task, who maintains it, and which agents it runs on.

• Best agent Skills for code review

  The best agent Skills for reviewing code before merge — structured, severity-tagged reviews and security-first passes across Claude Code, Cursor, and Codex.

• Best agent Skills for security & auditing

  The best agent Skills for security review and vulnerability detection — firm-grade static analysis (CodeQL, Semgrep), Kubernetes hardening, and real-exploit validation.

• Best agent Skills for testing & QA

  The best agent Skills for writing and running tests — Playwright web-app testing, browser automation patterns, and test-driven-development workflows.

• Best agent Skills for DevOps & infrastructure

  The best agent Skills for DevOps work — CI/CD, containers, blue-green and canary deploys, Terraform, and Kubernetes hardening across AWS, GCP, and Azure.

• Best agent Skills for frontend & UI design

  The best agent Skills for building production-grade UIs — distinctive design direction, brand systems, theming, and shadcn/Tailwind defaults that avoid generic AI output.

• Best agent Skills for SEO & content

  The best agent Skills for SEO and content ops — keyword research, technical audits, GEO/AEO for AI search, blog drafting, and AI-text humanization.

• Best agent Skills for marketing & growth

  The best agent Skills for marketing teams — landing-page CRO, copywriting, LinkedIn content, email sequences, and the SEO/GEO bundle that powers organic growth.

• Best agent Skills for data analysis

  The best agent Skills for analyzing data — Excel modeling with real formulas, multi-source cited research, primary-source data feeds, and publication-grade D3 visualization.

• Best agent Skills for document processing

  The best agent Skills for working with documents — Anthropic's official pdf, docx, xlsx, and pptx Skills, each with tested scripts for the format edge cases improvised code misses.

• Best agent Skills for web scraping

  The best agent Skills for scraping the web — firecrawl for agent-native extraction at scale, browser-use and playwright-skill for JavaScript-heavy pages, and ethical rate-limited scraping patterns.

• Best agent Skills for databases

  The best agent Skills for database work — vendor-published skills for Supabase/Postgres and PlanetScale/MySQL, plus Prisma ORM, MongoDB, and Redis caching patterns.

• Best agent Skills for email

  The best agent Skills for email — Resend's first-party transactional skill, its deliverability playbook, React email templates, Twilio for SMS/WhatsApp, and Anthropic's drip-campaign skill.

• Best agent Skills for diagrams

  The best agent Skills for generating diagrams — Mermaid from prose with self-validating syntax, Excalidraw whiteboard sketches, C4 architecture diagrams, and D3 data-driven visualization.

• Best agent Skills for workflow orchestration

  The best agent Skills for orchestrating multi-step work — superpowers for a full engineering pipeline, ADR and system-design skills for decisions, multi-agent parallelism, and app-integration routing.

• Best agent Skills for payments & billing

  The best agent Skills for Stripe and payments work — Stripe's own integration playbook, a checkout/subscriptions implementation Skill, Lemon Squeezy store operations, and safe Stripe API-version upgrades.

• Best agent Skills for Claude Code

  The best verified Skills to install in Claude Code, in install order — frontend-design for UI, superpowers for multi-step work, simplify for review, skill-creator for writing your own, and the Anthropic document Skills for real files.

• Best agent Skills for Cursor

  The best SKILL.md agent Skills verified working in Cursor — 78 of 191 catalogued Skills, led by frontend-design, superpowers, and the vendor-published Stripe, Supabase, and Resend Skills.

• Best agent Skills for Codex CLI

  The best SKILL.md Skills verified in OpenAI's Codex CLI — 51 of 191 catalogued Skills, led by frontend-design, superpowers, Trail of Bits security review, and the vendor Skills from Stripe, Paddle, Resend, and Supabase.

• Best agent Skills for Claude.ai

  The best Skills to upload to Claude.ai — the Anthropic document Skills (pdf, docx, xlsx, pptx) for real files, frontend-design and web-artifacts-builder for artifacts, and the marketing set for non-engineering teams.

• Best agent Skills for the Claude API

  The best Skills to use through the Claude API and Skills SDK — the document Skills for file generation in production, firecrawl and Valyu for retrieval, and Composio for tool routing.

• Best agent Skills for Gemini CLI

  The Skills verified working in Google's Gemini CLI — 11 of 191 catalogued, led by frontend-design, Firebase Hosting, the Stripe set, and Composio.

• Best agent Skills for Antigravity IDE

  The best Skills for Antigravity IDE, which ships a large pre-installed bundle — what is already there, what is worth adding on top, and the 36 Skills verified on this surface.

• Best Skills for writing client proposals

  The best agent Skills for turning a brief into a client-ready proposal — docx for the Word deliverable, pdf to read the RFP, brand-review to catch voice drift, and doc-coauthoring for the redline round. All four run on Claude.ai with no terminal.

• Best Skills for writing your newsletter

  The best agent Skills for a recurring newsletter — content-creation for the issue itself, email-sequence for automated flows, internal-comms for team and investor updates, and brand-review as the pre-send voice check. All four run on Claude.ai with no terminal.

• Best Skills for social media content

  The best agent Skills for social content as a founder — linkedin-content-skill for long-form posts and carousels, content-creation for the multi-channel version, canvas-design for the image, and brand-review before anything ships. All four run on Claude.ai with no terminal.

• Best Skills for building a pitch deck

  The best agent Skills for a pitch deck — pptx for the slides themselves, competitive-brief for the market and positioning slide, xlsx for the numbers behind the projections, and canvas-design for cover and section visuals. All four run on Claude.ai with no terminal.

• Best Skills for market and competitor research

  The best agent Skills for sizing up a market without hiring an analyst — competitive-brief for the positioning read, user-research to plan what to ask, research-synthesis to turn the answers into themes, and seo-audit for what your market is actually searching for. All four run on Claude.ai with no terminal.

• Best Skills for building a landing page

  The best agent Skills for a landing page that does not look AI-generated — frontend-design for the visual direction, web-artifacts-builder to produce the actual page, ux-copy for the words on it, and accessibility-review before it ships. All four run on Claude.ai with no terminal.

• Best Skills for monthly reports and spreadsheets

  The best agent Skills for the monthly numbers — xlsx for the model with real formulas, performance-report for the marketing summary, pdf to pull figures out of statements, and pptx to turn it into the review deck. All four run on Claude.ai with no terminal.

Or browse every Skill that runs without a terminal.

• Agent Skills vs Cursor Rules

  Cursor Rules are always-on, repo-specific instructions; agent Skills load on trigger and can bundle scripts and reference files. Use Rules for constraints that must apply to every edit, Skills for methods you invoke deliberately.

• Agent Skills vs AGENTS.md

  AGENTS.md is one always-read file describing a repo to any agent; Skills are installable, triggerable capability bundles. Write AGENTS.md for orientation, Skills for procedures.

• Agent Skills marketplaces and directories compared

  Where to get SKILL.md agent Skills in 2026 — the official Anthropic repo, install-count leaderboards, raw GitHub indexes, vendor repos, curated lists, and curated directories — and which to use for which job.

• How to audit an agent Skill before you install it

  A Skill is instructions your agent will follow and may bundle executable scripts. A ten-minute audit — read the SKILL.md, check provenance and licence, inspect bundled scripts, check what credentials it wants — catches almost everything that goes wrong.

• Do agent Skills cost tokens? Progressive disclosure explained

  Yes — about 100 tokens of metadata per installed Skill on every session, plus the full instructions only when a Skill triggers. That three-tier model is why a detailed Skill is cheaper than the long prompt it replaces.

• How to publish an agent Skill and get it listed

  Publish a Skill by putting SKILL.md in a public repo with a real licence and a description that triggers, then make it installable in one command. What we check before listing, and how to submit.

• How to deploy a website with AI agent Skills

  The complete guide to deploying and publishing a website from chat using SKILL.md agent Skills — which skill to use per host (Vercel, Netlify, Cloudflare, Firebase, GitHub Pages), per agent, with step-by-step and a platform matrix.

• Best agent Skills for deploying websites

  The six best verified agent Skills for deploying and publishing websites in 2026, ranked by what they deploy, who maintains them, and which agents they support.

• Deploy a website to Vercel from chat with an AI agent

  Use the vercel-deploy-claimable Skill to ship a site to a live Vercel URL from Claude Code or Cursor, then claim it into your own account.

• Deploy a website to Netlify with an AI agent

  Use Netlify's first-party netlify-deploy Skill to authenticate, create Deploy Previews, and promote a production deploy from Claude Code.

• Deploy a website to Cloudflare Workers & Pages with an AI agent

  Use Cloudflare's first-party platform Skill to deploy Workers and Pages, configure Wrangler, and manage KV/D1/R2 from chat.

• Deploy a static site to GitHub Pages with an AI agent

  Use the github-pages Skill to enable Pages, generate the GitHub Actions workflow, and set up a custom domain for a static site straight from a repo.