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 arcasilesgroup/ai-engineering --skill design-checkgit clone --depth 1 https://github.com/arcasilesgroup/ai-engineeringWrote 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/arcasilesgroup/ai-engineering/design-check)<a href="https://agentmods.dev/skills/arcasilesgroup/ai-engineering/design-check"><img src="https://agentmods.dev/badge/skills/arcasilesgroup/ai-engineering/design-check/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/arcasilesgroup/ai-engineering/design-check"><img src="https://agentmods.dev/badge/skills/arcasilesgroup/ai-engineering/design-check.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 | $0.00084 | $0.01817 |
| Opus 5.5 | $0.00034 | $0.00727 |
| Sonnet 5.5 | $0.00017 | $0.00363 |
| Haiku 4.5 | $0.00008 | $0.00182 |
Grade A, and why
design-check 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 1mo 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 — 152 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Design conformance check
Verify the code against the design document. The deliverable is a traceability table: every requirement in the spec mapped to the code that implements it, or marked as missing. No requirement may be silently dropped.
Read .claude/review/CONVENTIONS.md first — stack detection, severity, the
false-positive gate, and the report format. The installed-version rule there
applies: never call an implementation wrong based on remembered framework
behavior.
1. Locate the spec
In order: a path given in the skill arguments → design.md at the repo root →
docs/design.md, DESIGN.md, design/*.md, specs/*.md, docs/specs/*.md,
docs/rfcs/*.md, an adr/ directory, or a PRD directory the project documents
in its README/CONTRIBUTING. If the project has its own spec convention,
follow it over this list.
If no design document exists, stop. Do not invent requirements, and do not
substitute README.md, CLAUDE.md, or AGENTS.md — those describe setup and
agent rules, not intended behavior. Report:
No design document found (looked at:
<paths>). A conformance check needs a spec to check against. Point me at the file, or I can draft adesign.mdfrom the current implementation for you to correct — but note that a spec reverse- engineered from code cannot find design drift, since it would encode whatever the code already does.
Then stop and wait. Do not proceed to a general code review — that is code-audit.
2. Extract requirements
Read the spec end to end, then decompose it into atomic, checkable
requirements. Assign each a stable ID (R1, R2, …) and keep the spec's own
section names.
A good requirement is one you could write a test for. Split compound sentences: "the list paginates at 20 items and persists sort order across reloads" is two requirements, and they can have different verdicts.
Capture all three kinds, and label which each is:
- Behavioral — what the app does (routes, states, flows, validation, errors)
- Structural — architecture, file layout, data shapes, module boundaries
- Visual/UX — layout, copy, spacing, responsive breakpoints, states
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.
- 1mo ago First seen · 152 lines · 84 tokens per session scan A 577cae675233
design-check is a skill published in the GitHub repository arcasilesgroup/ai-engineering (61 stars, last pushed 2d ago), licensed Apache-2.0. It adds 84 tokens to every session and 1,817 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 2026-09-12.
Other skills, from other repositories
code-review
Review pull requests for repository fit, meaningful value, trustworthy provenance, differentiation, and maintainability in awesome-copilot.
spec-kitty-mission-review
Review a fully merged Spec Kitty mission post-merge (all WPs done/approved) to verify spec→code fidelity, FR coverage, drift, risks, and security. Triggers: "review the merged mission", "post-merge mission review", "verify the completed mission", "audit the mission implementation", "mission-level acceptance review"…
code-review-csharp
Perform structured code reviews of C# source code covering naming conventions, performance, security, readability, and .NET best practices. Trigger phrases include "review this C# code", "check my C# for best practices", "analyze this C# class", "find issues in my C# code".
mcp-server-review
Review a Model Context Protocol (MCP) server implementation against the 2026-07-28 protocol revision, which removed the initialize handshake and Mcp-Session-Id and made the protocol stateless. Use when the user asks to review, audit, upgrade or migrate an MCP server, asks whether their MCP server is spec compliant…
spec-kitty-runtime-review
Review runtime-owned outputs using the Spec Kitty review workflow surface, then direct approval or rejection with structured feedback. Triggers: "review this work package", "check runtime output", "approve this step", "review WP", "is this WP ready to approve", "check this implementation". Does NOT handle: setup-only…
adversarial-squad
Deploy a bounded, profile-loaded adversarial review squad at an SDD point-cut (post-spec, post-plan, post-tasks, pre-merge, or an ad-hoc decision) so independent doctrine lenses converge on findings one reviewer would miss. Triggers: "deploy a squad", "adversarial squad", "post-tasks anti-laziness pass", "pre-spec…