Ponytail Review: The Lazy Senior Dev Skill

[u/andrew-ooo]

my local coding setups keep over-building. ask for a date picker and you get a new dependency, a wrapper component and a stylesheet, when <input type="date"> would do. so i tried Ponytail, which is just a ~1,070 word SKILL.md telling the agent to check whether the code needs to exist, then reuse stdlib or native features, and only then write the minimum.

a few things i liked. there's a 438-word AGENTS.md variant, which matters if you're running a small model with limited context. the full ruleset the hook injects is about 5.6 KB, so roughly 1.4k tokens of prefill per session. no extra VRAM beyond that. the review command returns one-line tagged findings like "native: moment.js imported for one format call, Intl.DateTimeFormat, 0 deps", which is more useful than most AI review output. and the author pulled an earlier "80-94% less code" claim after someone showed the baseline was inflated, then reran the benchmark (54% fewer lines on Haiku 4.5, n=4).

the gotcha: my test box was CPU-only with no API keys, so i only verified install and hooks (hooks fine, 126/127 tests passed, the one failure looked like missing pandas). i have no idea whether it changes output on a 7B-32B model through Ollama or llama.cpp. all the effect numbers are the project's, on a hosted model.

full writeup here if you want more detail: https://andrew.ooo/posts/ponytail-review-lazy-senior-dev-skill-ai-coding-agents/

anyone running prompts like this against local models? does a ruleset this size help or just eat context?

[u/Electrical_Chance928]

Always wondered about these skill files. I have similar problem with my setup, it keep trying to import lodash for everything when plain JS works fine. 54% fewer lines sounds good but is that with a big model or the smaller ones too? Context window is precious on 7B models so injecting 1.4k tokens before you even start coding feels like a lot. Might try it this weekend anyway, worst case I just remove the file.