A general agent can write, search and use tools, but may not know a company’s procedure. A skill fills that gap with a folder containing a `SKILL.md` file, instructions and optional scripts or references. Anthropic says it created the format for Claude Code, opened it in December 2025 and transferred its name, logo, domain and GitHub organization to the AAIF on October 22, 2026. Its claims of more than 70 integrations, one million published skills and nearly 280 million installations need independent measurement.

A procedure packaged for an agent

The practical promise is portability.

A quality-control checklist or reporting workflow could be documented once, versioned and used by several compatible agents.

Less lock-in, if compatibility holds

Foundation ownership does not guarantee identical behavior: vendors may interpret instructions differently, restrict scripts or keep proprietary features.

Foundation ownership does not guarantee identical behavior: vendors may interpret instructions differently, restrict scripts or keep proprietary features.

The new supply-chain risk

Installing a skill means trusting instructions and sometimes code. It may request access to files, email or software repositories.

Organizations should verify authors, review scripts, restrict permissions, pin versions and log actions. Popularity is not a security audit.

The beginning of a common layer

AAIF stewardship can make skills a shared layer for agents.

Conclusion

Their value will depend on delivering portability without turning reusable know-how into a supply-chain risk.