Report · marked 25 Aug 2026

DietrichGebert/ponytail

Solid foundations, held back in a few specific places.

JavaScript · 110,914 stars · 159 files · branch main

78 /100 A-

Instructions 21/27Whether the repo tells an agent how to behave before it starts guessing. Losing marks on instruction quality.Setup 10/18Whether an agent can install the project and get it running without a human. Losing marks on deterministic install and pinned runtime version.Verification loop 19/25Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy. Losing marks on lint and format rules and static type checking.Context economy 20/20Whether the repo fits in a context window, or fights it. Full marks.Navigability 8/10How quickly anything new can orient itself. Losing marks on written documentation.

Higher is better. Accent marks what is costing you most.

Fix these first

Deterministic install

Commit the lockfile your package manager generates. Without it, an agent's install and your install are different builds, and 'works on my machine' becomes unfalsifiable.

Instruction quality

Worth fixing: it never states a build, test, or run command; has no code blocks.

Lint and format rules

A formatter config is the cheapest way to stop reviewing whitespace in agent diffs. It moves style from opinion to a command.

The full marking

Every deduction below names the file or setting it came from.

Instructions 21/27 A-

Whether the repo tells an agent how to behave before it starts guessing.

✓Agent instruction file 12/12

AGENTS.md is present, which is the format the most tools read.

Also found: Copilot instructions

✗Instruction quality 6/12

Real instructions, with gaps.

Worth fixing: it never states a build, test, or run command; has no code blocks.

2,589 characters, a workable length

uses headings, so an agent can skim it

✓README as an entry point 3/3

README has a clear getting-started section.

Setup 10/18 B-

Whether an agent can install the project and get it running without a human.

✗Deterministic install 0/6

No lockfile. An agent installing dependencies may not get what CI got.

Commit the lockfile your package manager generates. Without it, an agent's install and your install are different builds, and 'works on my machine' becomes unfalsifiable.

✓Discoverable commands 6/6

Commands are declared where an agent will look for them.

package.json scripts (test)

scripts/ directory

✓Environment config 4/4

.env.example documents what the app needs to run.

✗Pinned runtime version 0/2

No pinned runtime version.

Add a .nvmrc, .python-version, or equivalent so the agent's toolchain matches yours.

–Reproducible environment n/a

Not applicable — a library doesn't need a container to be worked on.

Verification loop 19/25 B+

Whether an agent can check its own work. This is the category that most decides whether agent output is trustworthy.

✓Tests exist 8/8

20 test files against 53 source files.

e.g. benchmarks/correctness.test.js, benchmarks/loc.test.js, pi-extension/test/extension.test.js

✓Test command is discoverable 7/7

An agent can find and run `npm run test`.

✓Continuous integration 4/4

2 GitHub Actions workflows define what "passing" means.

✗Lint and format rules 0/3

No linter or formatter config. Style is tribal knowledge, so agent output will drift from yours.

A formatter config is the cheapest way to stop reviewing whitespace in agent diffs. It moves style from opinion to a command.

✗Static type checking 0/3

No static type checking.

A type checker gives an agent an error message instead of a runtime surprise. It's the second-fastest feedback loop after the compiler.

Context economy 20/20 A+

Whether the repo fits in a context window, or fights it.

✓No committed build output 6/6

No generated directories committed.

✓.gitignore hygiene 3/3

.gitignore covers 13 patterns.

✓File sizes fit in context 6/6

No source file is large enough to crowd out a context window.

✓Repository weight 5/5

About 2.1MB checked out, which is comfortable.

Here is your AGENTS.md

Drafted from what is actually in this repository: the install command from your lockfile, the commands you already declare, your real directory layout. Anything marked TODO needs a person. Save it at the root as AGENTS.md.

AGENTS.md — drafted for DietrichGebert/ponytail

# AGENTS.md

Makes your AI agent think like the laziest senior dev in the room. The best code is the code you never wrote.

## Setup

```
npm install
```

## Commands

```
npm run test   # run the test suite, must pass before any commit
```

## Layout

- `benchmarks/`   17 source files
- `tests/`        15 source files
- `hooks/`        7 source files
- `scripts/`      5 source files
- `pi-extension/` 3 source files
- `ponytail-mcp/` 3 source files

## Conventions

- Tests live alongside the code they cover, following `benchmarks/correctness.test.js`.
- CI defines what passing means. See `.github/workflows/publish.yml`, and keep it green.
- TODO: add the two or three conventions a newcomer always gets wrong here.

## Gotchas

- Copy `.env.example` before running anything that needs configuration.
- No lockfile is committed, so an install here may not match what CI produced.

---

Drafted by agentreadme.com from what is in this repository. Everything marked TODO
needs a human. Check it in as AGENTS.md at the root.

Open the raw markdown or curl -o AGENTS.md agentreadme.com/draft/DietrichGebert/ponytail.md

Show the mark

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[![agent ready](https://agentreadme.com/badge/DietrichGebert/ponytail.svg)](https://agentreadme.com/DietrichGebert/ponytail)

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Think this mark is wrong?

Every deduction above names the file it came from, so this can be settled by looking. If a check missed something, that is a rule worth fixing.

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