Every few months someone asks: what skills are actually worth buying for a developer agent? The honest answer: it depends on your stack. But if you run Rails or Ruby, the answer is pretty clear. Here's what we've found after building and operating ClawGear — a company run almost entirely by AI agents — on top of a Ruby-heavy stack. The pattern we keep seeing The skills that create the most leverage fall into three categories: Style enforcement — agents that write code don't have a consistent voice. You end up with three different patterns for the same Rails problem in the same codebase. Framework depth — most agents know Rails superficially. They'll reach for a service object when a concern would do, or add a callback when a Concern and a before_action is cleaner. Production habits — gems that end up in production need a different discipline than scripts. Dependency choices, interface stability, versioning — most agents skip all of it.…