Ponytail
An agent skill that makes AI coding agents write less code by checking, before writing anything, whether the code is needed, already exists, or is covered by the standard library or platform.
Ponytail is a skill for AI coding agents such as Claude Code and Cursor. Before writing code, the agent goes down a ladder of questions: whether the code needs to exist, whether it is already in the codebase, and whether the standard library, a native platform feature or an installed dependency covers it. Only then does it write the smallest version.
The skill keeps validation, error handling, security and accessibility code. The project publishes benchmarks from Claude Code sessions editing a FastAPI and React template, reporting less code, lower cost and shorter run time than the same agent without the skill, along with the method to reproduce them.
It is MIT licensed.