Claude Skills are awesome, maybe a bigger deal than MCP

Summary

Claude Skills are awesome, maybe a bigger deal than MCP 16th October 2025 Anthropic this morning introduced Claude Skills, a new pattern for making new abilities available to their models: Claude can now use Skills to improve how it performs specific tasks. Skills are folders that include instructions, scripts, and resources that Claude can load when needed. Claude will only access a skill when it’s relevant to the task at hand. When used, skills make Claude better at specialized tasks like working with Excel or following your organization’s brand guidelines. Their engineering blog has a more detailed explanation. There’s also a new anthropic/skills GitHub repo. (I inadvertently preempted their announcement of this feature when I reverse engineered and wrote about it last Friday!) Skills are conceptually extremely simple: a skill is a Markdown file telling the model how to do something, optionally accompanied by extra documents and pre-written scripts that the model can run to help it accomplish the tasks described by the skill. Claude’s new document creation abilities, which accompanied their new code interpreter feature in September, turned out to be entirely implemented using skills. Those are now available in Anthropic’s repo covering .pdf, .docx, .xlsx, and .pptx files. There’s one extra detail that makes this a feature, not just a bunch of files on disk. At the start of a session Claude’s various harnesses can scan all available skill files and read a short explanation for each one from the frontmatter YAML in the Markdown file. This is very token efficient: each skill only takes up a few dozen extra tokens, with the full details only loaded in should the user request a task that the skill can help solve. Trying out the slack-gif-creator skill Here’s that metadata for an example slack-gif-creator skill that Anthropic published this morning: Toolkit for creating animated GIFs optimized for Slack, with validators for size constraints and composable animation pri...