Impeccable
bestofjs/bestofjs
A skill your agent uses when the user wants to design, redesign, shape, critique, audit, polish, clarify, distill, harden, optimize, adapt, animate, colorize, extract, or otherwise improve a…
Check whether the common Python code an LLM would plausibly write still works on this branch, testing real cases in ./playground against CPython.
Install Review Usability
$ npx skills add pydantic/monty --skill review-usability -a claude-codeProject install by default; add -g for ~/.claude/skills/.
$ gh skill install pydantic/monty review-usability --agent claude-codeProject scope by default; add --scope user for a personal install. Needs GitHub CLI 2.90.0 or later (public preview).
$ git clone --depth 1 https://github.com/pydantic/monty.git skills-src && mkdir -p .claude/skills && cp -r skills-src/.agents/skills/review-usability .claude/skills/review-usability && rm -rf skills-srcUse ~/.claude/skills/ instead of .claude/skills for a personal install. The folder must contain SKILL.md.
Claude Code skills documentation · loads skills from .claude/skills/
Install the "review-usability" agent skill from https://github.com/pydantic/monty/tree/main/.agents/skills/review-usability into .claude/skills/review-usability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "review-usability", then confirm the skill loads.Claude Code copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$skill-installer install https://github.com/pydantic/monty/tree/main/.agents/skills/review-usabilityType this inside Codex. $skill-installer <name> installs a curated skill from openai/skills. The installer writes to $CODEX_HOME/skills (default ~/.codex/skills). Restart Codex if the skill does not show up.
$ npx skills add pydantic/monty --skill review-usability -a codexProject install goes to .agents/skills/; add -g for ~/.codex/skills/.
$ gh skill install pydantic/monty review-usability --agent codexProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/pydantic/monty.git skills-src && mkdir -p .agents/skills && cp -r skills-src/.agents/skills/review-usability .agents/skills/review-usability && rm -rf skills-srcUse ~/.agents/skills/ instead of .agents/skills for a personal install.
Codex skills documentation · loads skills from .agents/skills/
Install the "review-usability" agent skill from https://github.com/pydantic/monty/tree/main/.agents/skills/review-usability into .agents/skills/review-usability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "review-usability", then confirm the skill loads.Codex copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add pydantic/monty --skill review-usability -a cursorProject install goes to .agents/skills/; add -g for ~/.cursor/skills/.
$ gh skill install pydantic/monty review-usability --agent cursorProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/pydantic/monty.git skills-src && mkdir -p .cursor/skills && cp -r skills-src/.agents/skills/review-usability .cursor/skills/review-usability && rm -rf skills-srcUse ~/.cursor/skills/ instead of .cursor/skills for a personal install.
Cursor skills documentation · loads skills from .cursor/skills/, .agents/skills/, .claude/skills/, .codex/skills/
Install the "review-usability" agent skill from https://github.com/pydantic/monty/tree/main/.agents/skills/review-usability into .cursor/skills/review-usability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "review-usability", then confirm the skill loads.Cursor copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gemini skills install https://github.com/pydantic/monty.git --path .agents/skills/review-usability--scope user (default) or --scope workspace; --path is the subfolder of the repo that holds the skill; --consent skips the security confirmation prompt.
$ npx skills add pydantic/monty --skill review-usability -a gemini-cliProject install goes to .agents/skills/; add -g for ~/.gemini/skills/.
$ gh skill install pydantic/monty review-usability --agent gemini-cliProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/pydantic/monty.git skills-src && mkdir -p .gemini/skills && cp -r skills-src/.agents/skills/review-usability .gemini/skills/review-usability && rm -rf skills-srcUse ~/.gemini/skills/ instead of .gemini/skills for a personal install, then run /skills reload.
Gemini CLI skills documentation · loads skills from .gemini/skills/, .agents/skills/
Install the "review-usability" agent skill from https://github.com/pydantic/monty/tree/main/.agents/skills/review-usability into .gemini/skills/review-usability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "review-usability", then confirm the skill loads.Gemini CLI copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ gh skill install pydantic/monty review-usabilityInstalls for Copilot at project scope by default; add --scope user for a personal install. Preview a skill first with gh skill preview. Needs GitHub CLI 2.90.0 or later (public preview).
$ npx skills add pydantic/monty --skill review-usability -a github-copilotProject install goes to .agents/skills/; add -g for ~/.copilot/skills/.
$ git clone --depth 1 https://github.com/pydantic/monty.git skills-src && mkdir -p .github/skills && cp -r skills-src/.agents/skills/review-usability .github/skills/review-usability && rm -rf skills-srcUse ~/.copilot/skills/ instead of .github/skills for a personal install. Commit .github/skills so cloud agent and code review can use it.
GitHub Copilot skills documentation · loads skills from .github/skills/, .claude/skills/, .agents/skills/
Install the "review-usability" agent skill from https://github.com/pydantic/monty/tree/main/.agents/skills/review-usability into .github/skills/review-usability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "review-usability", then confirm the skill loads.GitHub Copilot copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
$ npx skills add pydantic/monty --skill review-usability -a opencodeOpenCode documents no install command of its own. Project install goes to .agents/skills/; add -g for ~/.config/opencode/skills/.
$ gh skill install pydantic/monty review-usability --agent opencodeProject scope by default (.agents/skills/); add --scope user for a personal install.
$ git clone --depth 1 https://github.com/pydantic/monty.git skills-src && mkdir -p .opencode/skills && cp -r skills-src/.agents/skills/review-usability .opencode/skills/review-usability && rm -rf skills-srcUse ~/.config/opencode/skills/ instead of .opencode/skills for a personal install.
OpenCode skills documentation · loads skills from .opencode/skills/, .claude/skills/, .agents/skills/
Install the "review-usability" agent skill from https://github.com/pydantic/monty/tree/main/.agents/skills/review-usability into .opencode/skills/review-usability/ in this project. Copy the whole folder (SKILL.md and every file beside it), keep the folder name "review-usability", then confirm the skill loads.OpenCode copies the folder itself, the same result as the manual copy. Check what it changed before you commit it.
Facts
- Skill name
review-usability- GitHub stars
- 8.6k
- Token cost
- ~410 tokens
- SKILL.md length
- 196 words
- Files
- 1
- Skills in repo
- 9
- Repo updated
- First seen
- Licence
- MIT
At a glance
Check whether the common Python code an LLM would plausibly write still works on this branch, testing real cases in ./playground against CPython.
- Works in 4 steps: For each feature the branch touches,… → Write real test files in playground/… → Run each under both and diff → …
- Find behaviour that diverges from CPython
- Calls git
- Trips up ordinary idiomatic code
What it does
Review Usability is an agent skill from pydantic/monty, published by the product's own GitHub organization. Check whether the common Python code an LLM would plausibly write still works on this branch, testing real cases in ./playground against CPython. Use to find behaviour that diverges from CPython or trips up ordinary idiomatic code.
Its SKILL.md is about 410 tokens, which your agent loads only when the skill is triggered. It is a single SKILL.md file with no bundled scripts.
It sits in Frontend & Design, covering UX design. It works with Python. The repository describes itself as: A minimal, secure Python interpreter written in Rust for use by AI. The licence is MIT.
When your agent uses it
- Find behaviour that diverges from CPython
- Trips up ordinary idiomatic code
Example prompts
- “/review-usability”
Requirements
- Python 3
Workflow steps
4 steps, taken from the first numbered list in SKILL.md.
- For each feature the branch touches, list the idioms a model reaches for first — the
- Write real test files in playground/ (see python-playground), named recognisably.
- Run each under both and diff
- Prioritise silent divergence — same code, different result — over a clean
What it can do on your machine
Read from SKILL.md and the folder at commit 5915273. It shows what the files ask for, not the result of running them.
Tool permissions
Pre-approves nothing: there is no allowed-tools line, so your agent's usual permission prompts apply.
From allowed-tools in the SKILL.md frontmatter.
Runs code
Shell commands in SKILL.md call:
git
From the folder's file list and the shell code blocks in SKILL.md.
Network
No URLs in SKILL.md. Its commands use git, which can reach the network depending on how they are called.
From URLs in SKILL.md, links to its own repository left out.
Credentials
Names no API keys, tokens, secrets or passwords.
From names ending in _API_KEY, _TOKEN, _SECRET, _KEY or _PASSWORD in SKILL.md.
Context cost
Review Usability loads about 410 tokens when it runs. Until then it costs about 62 tokens; SKILL.md has 196 words of instructions outside code blocks.
Estimates: characters ÷ 4, the usual rule of thumb; real counts depend on the model's tokenizer. Scripts and assets cost tokens only if the agent reads them.
Safety
Auto-check passed
The automated check found no risky patterns in SKILL.md.
Automated static check — not a guarantee. Review scripts before installing. It scans the text of SKILL.md for risky patterns (piping downloads into a shell, reading credential files, hidden Unicode, destructive commands); files beside SKILL.md are not scanned.
SKILL.md
The full file from pydantic/monty at commit 5915273, republished under its MIT licence (© pydantic). 196 words, ~410 tokens.
Download SKILL.mdSave it as
.claude/skills/review-usability/SKILL.md (or your agent's skills folder).- name
- review-usability
- description
- Check whether the common Python code an LLM would plausibly write still works on this branch, testing real cases in ./playground against CPython. Use to find behaviour that diverges from CPython or trips up ordinary idiomatic code.
Usability review
Monty exists so LLMs can write Python that calls tools. Real usage is therefore the most common patterns, not exotic corners — and a divergence in a common pattern is the worst kind of bug, because the model has no way to know it must write something else.
Think hard on this one.
git diff origin/main...HEADFor each feature the branch touches, list the idioms a model reaches for first — the obvious method, argument form, combination with another builtin. Include ones the branch does not handle; that's where the gaps are.
Write real test files in
playground/(seepython-playground), named recognisably.Run each under both and diff:
bash uv run playground/test_thing.py # CPython cargo run -- playground/test_thing.py # MontyPrioritise silent divergence — same code, different result — over a clean
AttributeError. A missing feature that raises is recoverable; a wrong answer isn't.
An undocumented divergence is also a ./limitations/ finding.
Report
Per divergence: the code, CPython's output, Monty's output, how likely a model is to write it. Then unsupported-but-common idioms with the error the user sees, and briefly what worked — it bounds the review. Leave the playground files in place.
Report only, unless the user asks for fixes.
© pydantic, MIT. Rendered from Markdown: HTML in the file is shown as text, images as links, and headings moved down two levels. Raw file
Files
Just SKILL.md in .agents/skills/review-usability of pydantic/monty.
Open the folder on GitHubat commit 5915273
Compare with similar skills
Review Usability next to the 5 skills that share the most tags, products or categories with it. Stars are the repository's; “used in” counts other GitHub owners with a copy.
| Skill | Stars | Used in | Tokens | Auto-check | Licence | Repo updated |
|---|---|---|---|---|---|---|
| Review Usability this skillpydantic/monty | 8.6k | — | ~410 | Automated safety check: Pass | MIT | |
| Impeccablebestofjs/bestofjs | 3.1k | 27 repos | ~2.6k | Automated safety check: Pass | MIT | |
| DocsPrefectHQ/fastmcp | 28k | — | ~1k | Automated safety check: Pass | Apache-2.0 | |
| Interface Design for Dashboards and Appsholaboss-ai/holaOS | 11k | 3 repos | ~6k | Automated safety check: Pass | MIT | |
| Oil UIoil-oil/oil-ui | 1.1k | — | ~1.8k | Automated safety check: Pass | MIT | |
| Animategrowupanand/ConvoForm | 102 | 6 repos | ~1.9k | Automated safety check: Pass | Apache-2.0 |
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Related
Works with
Categories
Questions about Review Usability
What does Review Usability do?
Check whether the common Python code an LLM would plausibly write still works on this branch, testing real cases in ./playground against CPython. Review Usability is an agent skill from pydantic/monty, published by the product's own GitHub organization./playground against CPython.
When should I use Review Usability?
Review Usability fits situations like: find behaviour that diverges from CPython; trips up ordinary idiomatic code.
How do I install Review Usability in Claude Code?
Run `npx skills add pydantic/monty --skill review-usability -a claude-code`. Or copy the skill folder (.agents/skills/review-usability in pydantic/monty) into .claude/skills/review-usability in your project. Claude Code loads it when a task matches its description.
How do I install Review Usability in Codex?
Run `npx skills add pydantic/monty --skill review-usability -a codex`. Or copy the skill folder (.agents/skills/review-usability in pydantic/monty) into .agents/skills/review-usability in your project. Codex loads it when a task matches its description.
Can I use Review Usability in Cursor, Gemini CLI or GitHub Copilot?
Cursor, Gemini CLI, GitHub Copilot and OpenCode also load SKILL.md folders. With the skills CLI, run `npx skills add pydantic/monty --skill review-usability -a cursor` (or -a gemini-cli, github-copilot or opencode for the others). To copy it by hand, put the folder in .cursor/skills/review-usability, .gemini/skills/review-usability, .github/skills/review-usability and .opencode/skills/review-usability in your project.
What does Review Usability need to run?
Going by SKILL.md and its folder, Review Usability needs the command-line tools its instructions call (git). Our summary lists: Python 3.
Does Review Usability access the network?
SKILL.md contains no URLs. Its commands use git, which can reach the network depending on how they are called. This is read from the text; nothing was executed.
Is Review Usability safe to install?
Our automated static check of SKILL.md found no risky patterns, such as piping downloads into a shell, reading credential files or hidden Unicode. It is not a guarantee. Review the folder before installing.
What licence does Review Usability use?
Review Usability is published under the MIT licence (the repository's licence). It allows redistribution, so the full SKILL.md is shown on this page.
How many tokens does Review Usability use?
About 410 tokens (SKILL.md is roughly 1.6k characters). Agents keep only the skill's name and description in context until a task matches; then they load SKILL.md in full.
What are the alternatives to Review Usability?
Skills that share tags, products or a category with Review Usability: Impeccable (bestofjs/bestofjs, 3.1k stars), Docs (PrefectHQ/fastmcp, 28k stars), Interface Design for Dashboards and Apps (holaboss-ai/holaOS, 11k stars) and Oil UI (oil-oil/oil-ui, 1.1k stars). The comparison table on this page puts their stars, adoption, token cost, safety result and licence side by side.
Who maintains Review Usability?
pydantic (a GitHub organization, an official publisher) maintains it in pydantic/monty, which has 8,607 GitHub stars. The repository holds 9 skills in this directory. The repository was last updated on October 9, 2026.
Source: pydantic/monty on GitHub. Facts on this page come from the repository at the commit we read; the author's words are quoted as theirs.