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.

Controls your local Chrome over CDP to navigate, click, type, take screenshots and scrape data, reusing logged-in sessions. Official browser-use skill; install the browser-use CLI with uv first.

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.

Skills from security firm Trail of Bits: 40+ plugins for code auditing, CodeQL and Semgrep static analysis, differential review, smart-contract and cryptography audits, fuzzing and more. Also installable as a Claude Code or Codex plugin marketplace.

Turns the current folder into a teaching workspace you can resume across conversations: asks your learning goal, gathers reliable sources, builds short HTML lessons and cheat sheets, and tracks progress. Good for self-study and lesson prep; invoke manually (/teach), no API key.

A disciplined process for hard bugs and performance regressions: build a reliable reproduction loop, reproduce and minimize, form hypotheses, instrument to verify, then fix and add a regression test, redacting secrets in output. By Matt Pocock.

Forces red-green-refactor: write a test and watch it fail, then write the minimum code to pass. Any code written without a verified failing test gets deleted and redone. From the Superpowers workflow.

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.

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.

Drives local web apps with Python Playwright scripts to verify features, debug the UI, take screenshots and read browser logs. Includes helper scripts to start and stop dev servers. 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.

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.

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.

Engineering skill collection spanning define, plan, build, verify, review and ship, with /spec, /plan, /build, /test, /review and /ship commands, including TDD, code review and web performance audits. By Addy Osmani.

Helps subscription products reduce churn: designs cancellation flows, save offers and exit surveys, spots churn risk signals, and plans dunning and win-back emails after failed payments. For customer success, lifecycle and growth teams; billing platforms like Stripe need setup on your side.

Drafts, revises and reviews research manuscripts, tying every fact and number to verified evidence and covering reporting guidelines, authorship, AI disclosure and confidentiality; explicitly forbids fabricated citations or data. Includes offline check scripts; no API key needed.

Unified database lookup skill from K-Dense's scientific collection: reproducibly queries about 80 public database APIs such as PubChem, UniProt, ChEMBL, ClinicalTrials.gov and FRED, returning traceable results with endpoints, parameters and count checks. Some need API keys.

Systematic literature reviews following PRISMA and similar standards: searches PubMed, arXiv, bioRxiv and other databases, verifies each citation's DOI, and outputs Markdown and PDF in APA, Nature or other styles. Main web search uses parallel-cli and needs a Parallel account.

Teaches agents standard single-cell RNA-seq analysis with Scanpy: QC, normalization, PCA/UMAP, clustering, differential expression and plots, with ready-to-run pipeline scripts and guidance on converting Seurat and other R objects to h5ad. Needs Python 3.12+; by K-Dense.

Guides agents to the right statistical method for research data: t-tests, ANOVA, chi-square, regression and Bayesian analysis, checking assumptions, computing effect sizes and power, and reporting results in APA format. Python-based (pingouin, statsmodels); by K-Dense.

Skill suite for the whole academic research workflow: deep research (including PRISMA systematic reviews), paper writing, multi-perspective peer review and revision, pausing for human approval at each stage, with citation and integrity checks. CC BY-NC, non-commercial only.

Teaches agents to use the Chrome DevTools MCP efficiently: snapshot first to get element uids, screenshot only when needed, paginate and filter large output, inspect CSS and test browser extensions. Needs chrome-devtools-mcp configured; maintained by the Chrome DevTools team.

Teaches agents to read and write Obsidian vaults: Obsidian-flavored Markdown, Bases data views, JSON Canvas and the Obsidian CLI, plus Defuddle web content extraction and Knap template rendering. Maintained by Obsidian CEO kepano.