Productivity skills.

Critical-thinking adversarial reviewer skill. Use when you want Claude to deliberately stress-test a plan, design, or argument and surface the weakest links.

Collection of 20+ general-purpose skills by Jesse Vincent (obra) for thinking clearly, debugging, refactoring, planning, writing tests, and shipping code. The most popular community skill bundle.

Cut through ambiguity and push a task to completion. Use when a conversation is going in circles, scope is bloating, or the user explicitly wants to wrap something up fast.

Experimental skills lab by obra — early-stage ideas, in-progress skills, and prototypes. Useful if you want to track what's coming next.