Anthropic, OpenAI, and Microsoft Just Agreed on One File Format. It Changes Everything
Video: Anthropic, OpenAI, and Microsoft Just Agreed on One File Format. It Changes Everything. (26:19) → https://www.youtube.com/watch?v=0cVuMHaYEHE Published: 2026-03-30 | Views at capture: ~40,000
Abstract: Skills — agent-readable Markdown instruction files originally launched by Anthropic in October — have quietly become cross-industry infrastructure, now adopted by OpenAI, Microsoft Co-Pilot, Excel, and PowerPoint as a shared open standard. Nate argues that six months of community compounding means skills now outperform ad-hoc prompting at scale, and lays out a practical playbook for building agent-first skills that hold up in production pipelines. He also announces a community skills repository (part of OpenBrain on GitHub) curated specifically for domain-specific, knowledge-work use cases.
Highlights
- [01:01] From personal configs to org infrastructure — Enterprise admins now roll out skills workspace-wide, version-controlled and callable inside Excel, PowerPoint, Claude, and Co-Pilot. The methodology no longer lives in people's heads — it lives in a repository.
- [01:43] Agents have become the primary callers of skills — Agents make hundreds of skill calls per run; humans made a handful per conversation. Skills must now be designed agent-first, with descriptions that act as routing signals and outputs framed as API-style contracts.
- [04:37] The 10-second version + five things a good skill body needs — A skill is one folder, one
skill.md. The methodology body requires: (1) reasoning/frameworks, not just steps; (2) a specified output format; (3) explicit edge cases; (4) a worked example; (5) discipline to stay lean (≤100–150 lines — short skills that fire reliably beat long skills with competing instructions). - [10:20] Critical gotcha: description must stay on a single line — Code formatters that wrap the description across multiple lines will silently break skill triggering in Claude. Invest 80% of your attention in the description field.
- [13:13] Quantitative testing is now mandatory for agent-driven skills — When humans saw drift they could correct mid-conversation; agents have no recovery loop. Build a versioned test basket, quantify results, iterate. Treat skills like a tested API, not a vibe.
- [18:56] Three-tier team skills framework — Tier 1: standard brand/formatting skills (provision org-wide). Tier 2: methodology skills encoding senior-practitioner craft (highest value, hardest to surface). Tier 3: personal workflow skills (avoid keeping only on your laptop — make them team-legible).
- [22:45] Community skills repo launching inside OpenBrain (GitHub) — Focused on domain-specific knowledge-work skills (competitive analysis, financial model review, deal memos, research synthesis) with a consistent agent-readability bar applied to every entry.
References & Links
- 📺 Video: https://www.youtube.com/watch?v=0cVuMHaYEHE
- 🧠 OpenBrain (GitHub — community skills repo home): https://github.com/NateBJones/OpenBrain (mentioned in video)
- 📄 Anthropic Skills documentation: https://docs.anthropic.com/en/docs/build-with-claude/claude-skills (referenced)
- 🐦 Texas Paintbrush (real estate GP case study — 50k+ lines of skills across 50 repos): mentioned by handle on X
- 💬 Simon Willis prediction (skills > MCP) referenced from October 2025