Ponytail

Ponytail is a skill for Claude Code and compatible agents that pulls the model toward writing less. The repository reports roughly 54 percent less code on average, measured across twelve feature tasks on a real open-source project against the same agent without the skill, with results reaching 94 percent where the agent would otherwise over-build and near zero where the code was already minimal. It also reports about 20 percent lower cost and 27 percent faster runs. The authors note it keeps every safety guard, which a bare instruction to write one-liners did not.