Diagnose
A diagnosis loop that ends in a regression test, not just a green build.
Installation
$ npx skills add mattpocock/skillsThe CLI's unit is the repository, so this installs everything in mattpocock/skills, not diagnose alone. It writes into whichever agent directories it finds — Claude Code, Codex, Cursor, Copilot, Windsurf, Zed.
Summary
A diagnosis loop that ends in a regression test, not just a green build.
- Reach for it when a production bug where the fix matters less than making sure it cannot come back.
- Sits in Operate & maintain — production reality: debugging, performance, instrumentation, and writing down why the system is the way it is.
- Stack-agnostic — nothing in it assumes a particular language or framework.
- Published by Matt Pocock. Well regarded, but not the vendor of the thing it covers.
- Installing pulls the whole mattpocock/skills repository: this catalogue lists 6 other entries from it, and the repo may hold more.
Where it sits in delivery
Operate & maintainProduction reality: debugging, performance, instrumentation, and writing down why the system is the way it is.Everything in Operate →
The agent itself
The full text lives with its publisher and changes when they change it. Read it there rather than here — a mirrored copy of somebody else's procedure goes stale silently, and this page would have no way of telling you.
Related
More in Operate & maintain
- Browser testing with DevToolsUses the DevTools protocol to inspect, measure and reproduce behaviour in a live page.
addyosmani/agent-skills - GitHub triageTriages issues and pull requests into something a maintainer can work through.
trailofbits/skills - Analyzing .NET performanceTraces, dumps and allocation analysis, from the team that builds the runtime.Skill
dotnet/skills - Vercel optimizeFinding and fixing what is slow or expensive in a Vercel-hosted app.Skill
vercel-labs/agent-skills - Web performanceCloudflare's view of web performance — caching, edge behaviour and delivery.Skill
cloudflare/skills - AccessibilityWCAG in practice — semantics, focus management, contrast, and what automated checks cannot see.Skill
addyosmani/web-quality-skills