Content
88%Weight 40%Scale 1-5Reviews the quality of instructions and guidance provided to agents. Good implementation is clear, handles edge cases, and produces reliable results.
A strong operational runbook: fully executable commands for both Linux and macOS, per-step verification with a smoke test and explicit green criteria, and genuinely non-obvious operational rationale (unconditional image rebuild, minimal build context, read-only pnpm store). The only weaknesses are minor trimmable prose in the toolchain-image section and missed opportunities to offload background detail to reference files.
Suggestions
Trim the historical anecdote in section 4 ('went unnoticed for two weeks, costing ~25 minutes of package downloads on every review') to a single sentence stating the rule — an image from an older revision passes an existence check, so Docker's layer cache is the correct freshness gate.
Move the pnpm-store copy-up mechanics (~2.3 GB / ~12 s figures) and the store-poisoning security note from sections 4 and 6 into a short reference file (e.g. references/sandbox-internals.md), keeping SKILL.md focused on the setup steps.
Add a one-line preflight summary at the top mapping each symptom (docker MISSING, runsc MISSING, networking BROKEN) to its section number, so repairs can jump straight to the relevant step on re-runs.
| Dimension | Reasoning | Score |
|---|---|---|
Conciseness | The body is dominated by executable commands with brief, non-obvious rationale (e.g., 'never `.` (the repo root), which would ship the whole monorepo'), but a few passages could be trimmed — notably the anecdote 'which is exactly how an image predating the pnpm-store warming went unnoticed for two weeks, costing ~25 minutes of package downloads' and the dense copy-up cost prose in section 4. This is 'efficient; minor instances of over-explanation' rather than the lean every-token-earns-its-place anchor 5. | 4 / 5 |
Actionability | Every step is backed by copy-paste-ready commands covering both platforms: 'docker info >/dev/null 2>&1', the full gVisor apt/gpg install block, 'sudo modprobe veth', 'bash tools/review-sandbox/build-image.sh', and the smoke-test 'docker run --rm $RUNTIME nx-review-sandbox:latest bash -c ...' with the RUNTIME placeholder resolved by an in-line comment. The common cases (Linux and macOS, present vs MISSING) are all covered. | 5 / 5 |
Workflow Clarity | A clearly sequenced 6-step process with explicit validation: 'Run `uname -s` first', OK/MISSING checks at each step, a recovery loop ('Then re-check the runtime line above'), error-path handling for the BTF mismatch ('the running kernel no longer matches its on-disk modules ... **reboot**'), and a final smoke test with an explicit success criterion ('Green when: the kernel is NOT your host kernel, and node/java/dotnet report versions'). | 5 / 5 |
Progressive Disclosure | Sections are well-organized and appropriately command-first, with the only external pointers being repo scripts ('tools/review-sandbox/build-image.sh', 'tools/review-sandbox/sandbox prune') that are clearly signaled. However, at ~109 lines with no bundle references, some inline content — the multi-paragraph rationale in section 4 and the disk-reclamation/security notes in section 6 — could live in a one-level-deep reference file, leaving SKILL.md a leaner overview. | 4 / 5 |
Total | 18 / 20 Passed |