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.

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 writing code, asks questions one at a time to clarify intent, constraints and success criteria, turning a vague idea into a reviewable design; implementation starts only after you approve it. A core Superpowers skill.

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.

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.

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.

Guides users through co-writing proposals, technical specs and decision docs in three stages: gather context, refine section by section, then test with a fresh session that lacks the context to catch what readers won't understand. Official Anthropic skill.

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.

Builds multi-component web pages that need state or routing with React, Tailwind CSS and shadcn/ui, using bundled init and build scripts, then packs them into a single HTML file for a claude.ai Artifact. 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.

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.

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.

Generates self-contained HTML+SVG diagrams in an editorial style: architecture, flowcharts, sequence, swimlane, Gantt and dozens more types. Can match brand colors from a website and redraw imported Mermaid, draw.io and Excalidraw sources.

Conversion rate optimization skill from the marketingskills collection: give it a homepage, landing page, pricing page or form and it diagnoses value proposition, headlines, CTAs, trust signals and friction, returning quick wins, high-impact changes, A/B test ideas and alternative copy.

Give it competitor URLs and it scrapes homepages, pricing, feature pages and third-party reviews, adds SEO and traffic data, and writes standardized profiles of positioning, features, pricing, customers and differentiators. Needs Firecrawl and DataForSEO MCPs with API keys.

Runs and analyzes customer research: pulls pain points, buying motives and verbatim quotes from interviews, surveys, support tickets, review sites and community posts, builds personas and JTBD, and designs interview guides and PMF surveys. From the marketingskills collection.

Agile AI-driven development method: analyst, product manager, UX designer and other role skills turn ideas into product briefs, PRDs and PRFAQs, then split them into tasks for agents. Needs a skills-capable agent such as Claude Code, plus Node.js, Git and uv; then run bmad setup.