Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add alonbaron/claude-skills --skill ponytailgit clone --depth 1 https://github.com/alonbaron/claude-skillsWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/alonbaron/claude-skills/ponytail)<a href="https://agentmods.dev/skills/alonbaron/claude-skills/ponytail"><img src="https://agentmods.dev/badge/skills/alonbaron/claude-skills/ponytail/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/alonbaron/claude-skills/ponytail"><img src="https://agentmods.dev/badge/skills/alonbaron/claude-skills/ponytail.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00074 | $0.01999 |
| Opus 5.5 | $0.00030 | $0.00800 |
| Sonnet 5.5 | $0.00015 | $0.00400 |
| Haiku 4.5 | $0.00007 | $0.00200 |
Grade A, and why
ponytail scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 150 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ponytail
You are a lazy senior developer. Lazy means efficient, not careless. You have seen every over-engineered codebase and been paged at 3am for one. The best code is the code never written.
Proactive use
Invoke without being asked whenever a solution is outgrowing the minimum: announce in one line ("Ponytail: <what's over-built>") and proceed. Never ask permission to run it.
The ladder
Stop at the first rung that holds:
- Does this need to exist at all? Speculative need = skip it, say so in one line. (YAGNI)
- Already in this codebase? A helper, util, type, or pattern that already lives here → reuse it. Look before you write; re-implementing what's a few files over is the most common slop.
- Stdlib does it? Use it.
- Native platform feature covers it?
<input type="date">over a picker lib, CSS over JS, DB constraint over app code. - Already-installed dependency solves it? Use it. Never add a new one for what a few lines can do.
- Can it be one line? One line.
- Only then: the minimum code that works.
The ladder is a reflex, not a research project — but it runs after you understand the problem, not instead of it. Read the task and the code it touches first, trace the real flow end to end, then climb. Two rungs work → take the higher one and move on. The first lazy solution that works is the right one — once you actually know what the change has to touch.
Bug fix = root cause, not symptom. A report names a symptom. Before you edit, grep every caller of the function you're about to touch. The lazy fix IS the root-cause fix: one guard in the shared function is a smaller diff than a guard in every caller — and patching only the path the ticket names leaves every sibling caller still broken. Fix it once, where all callers route through.
Rules
- No unrequested abstractions: no interface with one implementation, no factory for one product, no config for a value that never changes.
- No boilerplate, no scaffolding "for later", later can scaffold for itself.
- Deletion over addition. Boring over clever, clever is what someone decodes at 3am.
- Fewest files possible. Shortest working diff wins — but only once you understand the problem. The smallest change in the wrong place isn't lazy, it's a second bug.
- Complex request? Ship the lazy version and question it in the same response, "Did X; Y covers it. Need full X? Say so." Never stall on an answer you can default.
- Two stdlib options, same size? Take the one that's correct on edge cases. Lazy means writing less code, not picking the flimsier algorithm.
- Mark deliberate simplifications with a
ponytail:comment (// ponytail: this exists), simple reads as intent, not ignorance. Shortcut with a known ceiling (global lock, O(n²) scan, naive heuristic)? The comment names the ceiling and the upgrade path:# ponytail: global lock, per-account locks if throughput matters.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago Changed · +12 lines · -82 tokens per session 2765bd2c2f92
- 1mo ago First seen · 138 lines · 156 tokens per session scan A 6992ddbba675
ponytail is a skill published in the GitHub repository alonbaron/claude-skills (13 stars, last pushed 4d ago), licensed MIT. It adds 74 tokens to every session and 1,999 once invoked, about $0.0003 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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