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 tonydzi/second-brain-starter-kit --skill red-first-reviewgit clone --depth 1 https://github.com/tonydzi/second-brain-starter-kitWrote 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/tonydzi/second-brain-starter-kit/red-first-review)<a href="https://agentmods.dev/skills/tonydzi/second-brain-starter-kit/red-first-review"><img src="https://agentmods.dev/badge/skills/tonydzi/second-brain-starter-kit/red-first-review/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/tonydzi/second-brain-starter-kit/red-first-review"><img src="https://agentmods.dev/badge/skills/tonydzi/second-brain-starter-kit/red-first-review.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 | $0.00064 | $0.01891 |
| Opus 5.5 | $0.00026 | $0.00756 |
| Sonnet 5.5 | $0.00013 | $0.00378 |
| Haiku 4.5 | $0.00006 | $0.00189 |
Grade A, and why
red-first-review 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 11d 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 — 159 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Red-first review
A test that has never been shown failing is a claim, not a check. This skill turns that claim into a measurement: break the thing the test is supposed to protect, and see whether anything goes red.
Applied to someone else's pull request it answers one question a human reviewer cannot answer by reading: which of the guards this PR adds would survive being deleted? Those are the ones the author will regress next month without noticing.
When to use it
- reviewing a PR that adds a guard, a validation, a sanitiser, a redaction, a permission check — anything that says "no" on some paths
- someone claims a fix is covered by tests, and you want that claim measured
- you wrote a regression test yourself and want to prove it fails without the fix
- auditing a test file that has never failed in CI
Not for: pure refactors with no behavioural claim, docs, dependency bumps.
The procedure
0. Read the whole files, not the diff
The diff shows what changed. The bug is usually in what did not. Open every
touched source file end to end, and specifically look for sibling call sites:
if the PR guards delete, does rename reach the same object? If it guards one
endpoint, how many endpoints are there?
Write down the full list of places the PR's own reasoning applies to. That list, not the diff, is what you are about to measure.
1. Get the suite green before you touch anything
Check out the PR branch, install, run the tests it claims to affect.
A red baseline makes everything after it unattributable. If the suite is already failing, narrow the command until it is green, and check the same failures on the base branch by name — pre-existing failures reported as PR damage is the fastest way to lose a maintainer's trust.
2. Prove your test command reaches the code
Break the file under review on purpose (append raise RuntimeError("canary"))
and re-run. If the suite stays green, that command never imports the file, and
every "covered" verdict you are about to produce is an artefact of some other
test. mutmatrix.py does this automatically and refuses to continue.
What ships with it
4 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
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.
- 11d ago Changed · -1 lines 466b595dc1a0
- 14d ago Changed · +1 lines · -8 tokens per session a395bc50e6f5
- 16d ago Changed · +13 lines 31128e861330
- 25d ago First seen · 146 lines · 72 tokens per session scan A 39debf8395f8
red-first-review is a skill published in the GitHub repository tonydzi/second-brain-starter-kit (9 stars, last pushed today), licensed MIT. It adds 64 tokens to every session and 1,891 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 2026-09-24.
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