2025-10-16 Claude Skills are awesome, maybe a bigger deal than MCP

Claude Skills are awesome, maybe a bigger deal than MCP https://simonwillison.net/2025/Oct/16/claude-skills

Simon Willison’s article introduces Claude Skills, a new Anthropic feature that significantly enhances LLM capability by enabling specialized, modular task execution. Skills are folders containing a Markdown file with instructions, optional scripts, and resources that the model can load only when relevant, making them token-efficient and highly flexible.

Key points:

• What Skills Are:

  • Markdown-based instructions with optional YAML frontmatter.

  • May include scripts or resources to handle specialized tasks (e.g., Excel, PDFs, Slack GIFs).

  • Loaded only when needed, conserving token usage.

• How They Work:

  • Claude scans available skills on session start, reading short YAML summaries.

  • Full skill details are used only if a related task arises.

  • Require a coding environment with filesystem and script execution.

• Comparison to MCP (Model Context Protocol):

  • MCP is heavy, token-expensive, and protocol-driven.

  • Skills are lightweight, simple to create, and integrate seamlessly into coding agents.

  • MCP implementations often limit LLM performance due to context size.

• Applications & Potential:

  • Can create domain-specific “agents” (e.g., data journalism pipelines).

  • Easily shareable, simple to adapt, and not model-locked.

  • Expected to trigger a “Cambrian explosion” of community-made skills, overshadowing MCP adoption.

• Security & Safety:

  • Depends on sandboxed coding environments to prevent abuse and prompt injection risks.

Mermaid Diagram of Claude Skills vs MCP

This illustrates how Skills offer a lightweight, modular, and token-efficient alternative to MCP for enhancing LLM capabilities.