What's in your agent skill stack?

Skills and plugins are where most of the real gains in agent coding come from right now, and there are thousands of them. I'd like to build a list of the ones people actually keep installed.

Mine so far

• Superpowers: brainstorm, plan, test first, review. The process layer.

• Ponytail: stops the agent from writing code that doesn't need to exist.

• Karpathy guidelines: four rules in one CLAUDE.md.

• Cloudflare security-audit: multi-agent audit with verified findings.

• Anthropic skills: documents, design and a template for your own.

Your turn

Reply with:

• the skill or plugin, with a link

• the agent you run it in

• one line on what changed after you installed it

Bonus if you can point to a difference in your token usage on your Agent Usage profile. That's the kind of evidence that helps everyone pick.