Install these one at a time and use each one for a week before you add the next. That way you know which one actually helped. Copy this prompt into Claude Code, fill in the one you want and Claude sets it up.

1. Grill Me

Before Claude writes anything, it interviews you about your plan: a round of numbered questions, each with its recommended answer. It looks things up in your project itself and only asks you for the decisions, so the gaps you hadn’t thought of come out before the build.

Add it (type these inside Claude Code):

Use it: type /grill-me and describe what you’re about to build.

The catch: Run the setup command once in each project. It asks a couple of questions about where to save notes.

github.com/mattpocock/skills →

2. Karpathy guidelines

One single file of rules that stops Claude making assumptions about your code and changing things you never asked it to touch. Think before coding, keep it simple, make only the change you asked for.

Add it (type these inside Claude Code):

Use it: nothing to type. Once it’s installed, the rules sit in the background of every session.

The catch: It’s written by the community, based on Andrej Karpathy’s post about AI coding mistakes, not by Karpathy himself. Prefer it in one project only? The source page shows how to add the file to that project’s CLAUDE.md instead.

github.com/multica-ai/andrej-karpathy-skills →

3. Systematic Debugging

Instead of guessing at a fix, Claude forms a theory, narrows down where the problem is and proves the root cause before it changes anything.

Add it (type these inside Claude Code):

Use it: it kicks in on its own when you report a bug or a failing test. You can also say “use systematic debugging”.

The catch: It comes as part of Superpowers, which adds a whole plan-test-review way of working, not just this one skill.

Systematic Debugging in obra/superpowers →

4. Web App Testing

Published by Anthropic. Claude opens your app in a browser, clicks through it, takes screenshots, reads the error logs and reports what’s broken.

Add it (type these inside Claude Code):

Use it: “Use the web app testing skill to check my booking page on my local copy and report any errors.”

The catch: It tests and reports; fixing is a separate step you ask for. It’s for apps running on your own computer, and it uses Python and Playwright, which Claude can install for you. It comes in Anthropic’s example-skills bundle with a few others.

webapp-testing in anthropics/skills →

5. Handoff

Compresses your whole session into one markdown document, so you can start a fresh session with everything that matters and none of the clutter. That’s the fix for context rot, when Claude gets worse the longer a session runs.

Add it (type these inside Claude Code):

Use it: type /handoff near the end of a long session, then open a new one and point it at the document.

The catch: Already installed if you added Grill Me. It saves the document to your computer’s temporary folder, so move it somewhere safe if you want to keep it.

Prefer to do it by hand? My handoff file guide shows the six headings to use: wrightmode.com/handoff.

github.com/mattpocock/skills →

Sources checked 27/09/2026: each skill’s GitHub page linked above and Anthropic’s official plugin marketplace.