AnthropicCovers designing the tools rather than just exposing an API, in Python with FastMCP or in TypeScript with the MCP SDK. Most of the value is in the part about what makes a tool legible to a model.
In the author’s words
Guide for creating high-quality MCP (Model Context Protocol) servers that enable LLMs to interact with external services through well-designed tools. Use when building MCP servers to integrate external APIs or services, whether in Python (FastMCP) or Node/TypeScript (MCP SDK).
The description field from SKILL.md, quoted as written.
Read it before you install it
SKILL.md · 230 lines
Install on its own
Or add it to your stack above and install everything at once.
npx skills add https://github.com/anthropics/skills --skill mcp-builderTrust audit
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Goes well with
pick-ui-library
Picks the library from the set Emil actually uses and trusts.
Stops your agent hand-rolling a toast or installing whatever is trending. Covers components, motion, charts, interaction, state and styling.
npx skills add https://github.com/emilkowalski/skills --skill pick-ui-library
better-ui
Concentric radius, optical alignment, surface depth, hit areas.
Based on the Details That Make Interfaces Feel Better article. The small corrections that separate a shipped interface from a generated one.
npx skills add https://github.com/jakubkrehel/skills --skill better-ui
ordinary-interfaces
180 interface rules that each carry a number and its evidence grade.
Every rule states a value, cites whether that value is spec, measured or convention, and says where it stops applying. Reads your project's own tokens before it quotes a default, so a 7px radius in a 7px system is correct rather than a finding.
npx skills add https://github.com/Board-ly/ordinary-interfaces
Emil Kowalski
Jakub Krehel
Finn Marten