review-slice

review-slice is a command for coding agents from rockcrafters/mason. It costs 69 tokens per session (2,843 once invoked), scanned A, original, Apache-2.0.

A read-only checker for Chisel slice definition files (SDFs), which describe which parts of an Ubuntu package belong in a smaller system image. It reviews changes against the project's required format and conventions.

In plain words
What is it for?
Use it to review a slice file, branch, or pull request and receive a report covering checks, dependencies, naming, formatting, schema versions, tests, and forward-port needs.
Why use it?
It catches errors that may make a slice fail CI, omit needed dependencies, use incorrect names or paths, or miss release-specific requirements before the change is submitted.

Command

Part of the mason plugin — 2 skills, 2 commands shipped together

Install

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.

agentmods
npx agentmods add commands/rockcrafters/mason/review-slice
Clone the repo
git clone --depth 1 https://github.com/rockcrafters/mason

Or install mason, the plugin that ships this one along with the rest of its 2 skills, 2 commands.

Wrote 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.

agentmods badge for review-slice

README.md
[![agentmods](https://agentmods.dev/badge/commands/rockcrafters/mason/review-slice.svg)](https://agentmods.dev/commands/rockcrafters/mason/review-slice)
Your own site
<a href="https://agentmods.dev/commands/rockcrafters/mason/review-slice"><img src="https://agentmods.dev/badge/commands/rockcrafters/mason/review-slice.svg" alt="Measured on agentmods" height="20"></a>
Per session 69 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 2,843 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00069 $0.02843
Opus 5 $0.00034 $0.01422
Sonnet 5 $0.00014 $0.00569
Haiku 4.5 $0.00007 $0.00284

Measured 4d ago against content hash ac97eed908bc, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

review-slice 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 4d 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.

mason/skills/chisel-releases/commands/review-slice.md · 160 lines

How it starts

The opening of the file, as written. The whole thing — 160 lines — stays where its author put it; the contents beside it link to each section on GitHub.

You review slices in canonical/chisel-releases.

Prerequisites: read shared/CHISEL.md first for chisel/SDF format reference, branch model, schema versions, and canonical naming conventions. This agent focuses on what to check when reviewing.

You are read-only: inspect the diff / SDFs and return a review report. Do not edit files.


Deterministic first pass

Before reasoning about anything, run the deterministic checks over the diff. When reviewing a PR or branch, one command does it all -- pass the branch the PR targets:

scripts/review-diff.py --base <target-branch>

It finds the changed SDFs and runs the three checkers over them, then prints findings grouped by severity plus a verdict, and exits non-zero if anything blocks (the same command a CI PR-review job would call). The three it drives, also runnable on their own:

  • scripts/check-slice.py slices/<pkg>.yaml -- static conventions: sorting, naming, absolute paths, duplicate contents keys, copyright presence, clutter exclusion, arch names, version-gated fields (hint/prefer/v3-essential/essential-as-map/essential-as-list), and hint: length + mechanical style (the noun-phrase rule needs NLP -- validate-hints CI covers that, not this script). Reads format: from ./chisel.yaml (or pass --branch ubuntu-XX.XX).
  • scripts/check-test.py slices/<pkg>.yaml -- test coverage: warn if there's no test or it exercises none of the binaries; info listing untested binaries under partial coverage (normal for suites and alternatives symlinks -- judge whether the gaps matter).
  • scripts/check-diff.py --base <target-branch> -- append-only regressions: a removed SDF or slice fails the removed-slices CI gate (unless the package left the archive); a content path dropped from a kept slice has no CI gate but is a regression reviewers reject.

Fold the output straight into your report: map block -> blocking, warn -> should-fix, info -> judge. Then spend your own judgement on what they can't check: dependency accuracy, test depth, design, forward-porting, and hint phrasing (noun phrase, no finite verbs -- see shared/CHISEL.md).

None cut a rootfs or run tests -- chisel cut (the install-slices CI check) and spread cover those.


Read the full file on GitHub · 160 lines

Changes

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.

  1. 4d ago First seen · 160 lines · 69 tokens per session scan A ac97eed908bc

Subscribe to this mod's changes

review-slice is a command published in the GitHub repository rockcrafters/mason (3 stars, last pushed 1mo ago), licensed Apache-2.0. It adds 69 tokens to every session and 2,843 once invoked, about $0.0003 per session on Opus 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 2026-08-31.