Tools

Guides the agent through writing or improving a skill: clarify intent, draft SKILL.md, run scored evals with and without the skill, then tune the description so it triggers accurately. Official Anthropic skill.

Flags and rewrites AI-sounding text using 25 patterns drawn from Wikipedia's 'Signs of AI writing', keeping the meaning without inventing facts. Give it a writing sample to match your own voice.

166 research skills maintained by K-Dense (formerly Claude Scientific Skills), spanning bioinformatics, cheminformatics, clinical research, materials and physics, including unified access to 78 public databases such as PubChem and UniProt. Works with Claude Code, Codex and Cursor.

Anthropic's role-based skill collection covering sales, finance, legal, HR, support, marketing, product, design, operations and data analysis: over a hundred skills you can install one at a time. Works best with CRM, data warehouse and other connectors.

Before you build, the agent grills you on your plan or design, offering a recommended answer each round, until every decision branch is resolved. It calls the grilling skill from the same repo, so install both.

Resolves subscription billing issues: checks customer and subscription state, separates duplicate purchases, team seats and failed payments, restores self-serve before refunding, and drafts the reply. Needs Stripe or similar tools connected; refunds move real money, so review them.

Creates, reads and edits PowerPoint decks: applies templates and layouts, handles speaker notes and comments, and merges or splits slides. The official Anthropic skill behind Claude's document features; source-available, not open source.

After giving advice, a draft or a data analysis, adds 2-3 targeted follow-up questions that prompt the user to check key facts, test the reasoning and fill in missing context. Fires at most once per conversation. Official Anthropic skill.

Writes internal communications in familiar company formats: 3P updates, leadership reports, project status updates, company newsletters, FAQs and incident reports. Official Anthropic skill.

Makes GIFs that follow Slack's recommended size, frame rate, color and length for emoji (128x128) and message GIFs (480x480), with animation tips and tools to assemble and validate them. Built on Python and Pillow. Official Anthropic skill.

When answering questions about using Claude and its products, attaches a matching course, tutorial or case study from the Claude Academy catalog. Recommends only strong matches and never invents courses. Official Anthropic skill.

Creates, edits and analyzes Excel spreadsheets: formulas, formatting, charts and data cleaning, plus conversion between CSV, TSV and other tabular formats. The official Anthropic skill behind Claude's document features; source-available, not open source.

Reference for the Claude API and Anthropic SDK: model selection and pricing, streaming, tool use, prompt caching, Managed Agents and more, plus workflows for model migration and prompt audits. Official Anthropic skill.

Guides agents in building quality MCP servers: research the protocol and target API, design tools, implement with Python (FastMCP) or the TypeScript SDK, and write evaluation questions to test the result. Official Anthropic skill.

Develops a design philosophy first, then draws posters, illustrations and other static visuals in code, exporting PNG or PDF. Emphasizes original work rather than copying existing artists. Official Anthropic skill.

YC office hours skill from gstack: startup mode tests real demand, the narrowest wedge and future fit with six probing questions; builder mode brainstorms side projects, hackathons and open source. Ends with a design doc. Maintained by Garry Tan.

Skill pack from YC president Garry Tan: slash commands such as /office-hours, /plan-ceo-review, /review, /qa and /ship play CEO, engineering manager, designer, QA and release engineer. Needs Git and Bun; clone the repo and run ./setup as the README describes.

Official MoneyPrinterTurbo skill: give it a topic or script and the agent installs, configures and produces a short video with voiceover, stock footage, subtitles and music; defaults to Chinese vertical MP4. Needs an LLM API key and a free Pexels key; macOS and Windows.

For fuzzy requirements: the agent asks one question at a time with its own guess, clarifying users, motivation, success criteria and constraints, and restates the intent for your confirmation before planning. Needs you answering live, so not for unattended runs. From Addy Osmani's agent-skills.

Reads messy invoices and receipts (PDFs, scans, screenshots), extracts vendor, date and amount, renames and files them by vendor, category or year, keeps originals and can export a CSV for your accountant. Needs an agent with local file access; no account required.

Local job search workbench: evaluates role fit and spots fake listings, generates tailored resume and cover letter PDFs, and tracks applications without ever applying for you. Run npx @santifer/career-ops init first, then open Claude Code or Codex in the created folder.

Generates natively editable PPTX from PDFs, Word files, web pages and other sources, with native shapes, data charts and master layouts. Can also fill your own template and add animations and narration to finished decks. Needs Python 3.10+ and its dependencies.

Searches Reddit, X, YouTube, Hacker News, Polymarket and more in parallel for the past 30 days of discussion on a topic, scores it by engagement and summarizes it into a brief. Good for market research and meeting prep. Needs Python 3.12+; some sources need API keys.

Writes B2B cold emails and multi-step follow-up sequences, refining subject lines, openers, body and calls to action so they feel personal and human. Suited to SDRs and founders doing outbound. From the marketingskills collection; no extra account needed.