Chapter 18

Useful External Skills

A small shortlist for marketing, research, and maintaining your knowledge library. Pick the task first, then the Skill.

Choose by the job

Skill and sourceUseful forWhat you needCompatibility documented by authorReview status
Marketing Skills · Corey HainesChoose from a broad library covering CRO, copywriting, SEO, analytics, content, growth, and salesProduct context first; install only the skills needed for the taskClaude Code, Codex, Cursor, Windsurf, and Agent Skills-compatible agentsRepository reviewed; individual skills require separate testing
Copywriting · Corey HainesDraft a landing page from your offer and customer evidenceAudience, offer, proof, and page goal; preserve companion referencesClaude Code, Codex, other Skills-compatible agentsSource reviewed; no test run recorded
SEO Audit · Corey HainesProduce a prioritized list of site issuesSite access and business context; browser or crawl data for rendered checks; analytics access for performance questionsClaude Code, Codex, other Skills-compatible agentsSource reviewed; no test run recorded
No AI Slop · Peter YangEdit a draft to remove 20+ AI writing patterns while keeping your voice, or flag the patterns without rewritingA draft, plus its audience and where it will be published; no API keys or commandsClaude Code, Codex, ChatGPT plugin, other Skills-compatible agentsSKILL.md and eval.md reviewed; no test run recorded
Claude Watch · devinilabsTurn a tutorial into timestamped notes and screenshotsPublic video or local file, command execution, yt-dlp and ffmpeg; transcription credentials if neededClaude Code, Claude web bundle, Codex; environment capabilities still requiredREADME reviewed; no test run recorded
Obsidian Markdown · kepanoCreate notes with valid links, callouts, and propertiesAccess to the Markdown files in your vaultClaude Code, Codex, other Skills-compatible agentsRepository reviewed; no isolated test recorded
Defuddle · kepanoExtract readable article text for researchNode/npm, Defuddle CLI, command execution, and an accessible webpageClaude Code, Codex, other Skills-compatible agentsSource reviewed; no test run recorded
Excalidraw Diagram · coleam00Create editable Excalidraw diagrams from a concept, process, or system descriptionPython, uv, Playwright Chromium, and command execution for rendering and visual checksClaude Code, Codex, and other Skills-compatible coding agentsSource reviewed and installed locally; no isolated output test recorded
Archify · tt-a1iTurn a repository or system description into an interactive architecture, workflow, sequence, data-flow, or lifecycle mapNode.js 18+ and npm install for schema validation; browser access to review the HTML outputClaude Code, Codex CLI, Cursor, OpenCode, and Claude.ai with environment-dependent executionRepository reviewed; not installed or test-run locally

Hermes supports the Agent Skills format, but format compatibility alone does not confirm that a Skill's tools, commands, or dependencies work there. These entries have not been validated in Hermes.

Start with one small test

  • Writing: draft one page and check every claim against your supplied evidence.
  • Editing: run detect mode on one old post, then edit mode, and check the edit still sounds like you.
  • SEO: audit one page and manually verify the top three findings.
  • Video: process a short segment and compare timestamps and visible text with the video.
  • Notes: edit a sample note and check its links in Obsidian.
  • Clipping: extract one article and compare the result with the original.
  • Diagrams: map one small workflow, inspect the rendered output, and verify every connection against the source.

Install from the linked author's instructions, including required companion files. A Skill does not automatically provide account access, software dependencies, or permission to publish.

How entries earn a recommendation

Source reviewed means the stated workflow and setup were inspected. Tested requires a recorded task, environment, result, and limitation. Keep a Skill on this shortlist only while it has a clear use and a maintained setup path.

For guided examples, see Claude Can Watch YouTube Now and Remove AI Slop from Your Writing.

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