Claude Skills are awesome, maybe a bigger deal than MCP

claude-skillsmcpagentic-codingsimon-willisonanthropiccoding-environment

Abstraction: Claude Skills as lightweight Markdown-based agent capability extension beating MCP

Key points:

Skills are Markdown files with YAML frontmatter + optional scripts; harness scans them at session start for a few dozen tokens each, loading full content only when relevant — highly token-efficient
Anthropic introduced Skills in October 2025; Claude's document creation features (PDF, DOCX, XLSX, PPTX) are implemented as skills
Requires model access to a filesystem and command execution environment; depends on safe sandboxing
Compared to MCP (a full protocol spec with hosts, clients, servers, three transports): skills are dramatically simpler — "Markdown with a tiny bit of YAML"
MCP's GitHub integration reportedly consumes tens of thousands of tokens of context; skills avoid this overhead
Simon Willison: Claude Code is better understood as a general computer-automation agent, not just a coding tool; skills make this explicit

Connections: Anthropic · Claude Code · Simon Willison · AI Agents · Model Context Protocol · Agentic Coding