Tools

Extracts text and tables from PDFs; merges, splits and rotates pages, adds watermarks, fills forms and OCRs scanned documents. The official Anthropic skill behind Claude's document features; source-available, not open source.

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.

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.

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.

OCRs photos of visa documents such as bank, employment or income certificates, translates them into English and builds a side-by-side bilingual PDF. Needs Python (pillow, reportlab) and an OCR engine. Not an official certified translation: verify names, amounts and dates.

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.

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.

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.

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.

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

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.

Ten built-in color and font themes to apply to slides, documents, reports and HTML landing pages, or generate a new theme on demand. 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.

Creates, reads and edits Word documents: tables of contents, page numbers and letterheads, tracked changes, comments and find-and-replace, while preserving existing formatting. The official Anthropic skill behind Claude's document features; source-available, not open source.

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.

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.

Turns natural-language descriptions, Mermaid or a real code repo into interactive single-file HTML diagrams: architecture, flowcharts, sequence diagrams, data flows and state machines. Validates output automatically and exports PNG or SVG.

Curated index of Claude skills with about 30 practical skills in the repo (resume tailoring, content research and writing, file organization, meeting analysis) plus 800+ automation skills that reach third-party apps via Composio, which need Rube MCP and account authorization.

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.

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.

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.

Shapes the agent's replies for a reader with ADHD: lead with the next action, number multi-step work, restate progress every turn, hold back tangents, give concrete time estimates and make finished work visible. Turn it on with /i-have-adhd; it lasts until you say stop adhd mode.