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 youdotcom-oss/dx-toolkit --skill review-guidelinesgit clone --depth 1 https://github.com/youdotcom-oss/dx-toolkitWrote 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/youdotcom-oss/dx-toolkit/review-guidelines)<a href="https://agentmods.dev/skills/youdotcom-oss/dx-toolkit/review-guidelines"><img src="https://agentmods.dev/badge/skills/youdotcom-oss/dx-toolkit/review-guidelines.svg" alt="Measured on agentmods" 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 | $0.00028 | $0.00440 |
| Opus 5 | $0.00014 | $0.00220 |
| Sonnet 5 | $0.00006 | $0.00088 |
| Haiku 4.5 | $0.00003 | $0.00044 |
Grade A, and why
review-guidelines scanned grade A with 1 finding against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 7d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Runs shell commandslowCapability
Expected in a hook, worth knowing in a rule or an instructions file.
- `Bun.$\`cmd\`` over `child_process.spawn()` What it actually says
Review Guidelines
Additional checks for this codebase:
Code Quality
- Prefer
typeoverinterfacefor type definitions - Use arrow functions (
const fn = () =>) over function declarations - Use
#field(ES2022 private) instead ofprivate field(TypeScript) - No
anytypes — useunknownwith type guards - No index.ts files (except plugin entry points) — use feature-named re-exports
- Explicit
.tsextensions on all local imports - Object params when >2 args:
fn({ a, b, c }: { ... }) - Zod namespace import:
import * as z from 'zod' - Import directly from specific files, not through re-exports within a module
Testing
- Use
test()notit()for test declarations - No conditional assertions — assert the condition first
- Test both branches: try/catch, conditionals, fallbacks
- Prefer real dependencies over mocks for module resolution tests
- Organize with
describe()blocks
Bun Runtime
Bun.file()overfs.existsSync()/readFileSync()Bun.write()overwriteFileSync()Bun.$\cmd`overchild_process.spawn()`import.meta.diroverprocess.cwd()- Run commands from repo root with
bun --cwd packages/<name>— nevercdinto packages
Security
- Never commit secrets, API keys, or tokens
- Check for OWASP top 10, command injection, XSS
- Verify new dependencies for license compliance
- Watch for ReDoS patterns in regex
Breaking Changes
- Flag any changes to public API signatures
- Check for TSDoc
@publicmarkers on modified exports - Verify backward compatibility of Zod schema 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.
- 7d ago First seen · 51 lines · 28 tokens per session scan A 61e7d83b15c1
review-guidelines is a skill published in the GitHub repository youdotcom-oss/dx-toolkit (25 stars, last pushed 17d ago), licensed MIT. It adds 28 tokens to every session and 440 once invoked, about $0.0001 per session on Opus 5. A static security scan graded it A with 1 finding (runs shell commands). No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
Other skills, from other repositories
code-review
Reviews a supplied code path or diff for correctness, security, maintainability, and style without executing or modifying it.
knowledge-audit
Review and clean up stored memories — find duplicates, contradictions, stale entries, and consolidate.
gitnexus-pr-review
Use when the user wants to review a pull request, understand what a PR changes, assess risk of merging, or check for missing test coverage. Examples: "Review this PR", "What does PR #42 change?", "Is this PR safe to merge?".
tool-defs-analysis
Read-only audit of MCP definition language across an existing surface — tools, resources, prompts, server instructions. Walks every definition file and checks 16 categories the LLM reads to decide whether and how to call: voice & tense, internal leaks, audience leaks, defaults, recovery hints, field descriptions…
research-papers
Use when the user wants a literature review, paper summary, research landscape, or sourced synthesis from papers, reports, abstracts, or converted PDFs.
qa
QA test a live website with Axon discovery/content evidence plus browser automation when interaction is required. Use when the user wants exploratory QA, form testing, navigation/link checks, responsive checks, performance observations, bug reports, or a pre-launch quality review.