system-designer-review

system-designer-review is a skill for Claude Code from on-deck-society/love-stack. It costs 39 tokens per session (550 once invoked), scanned A, original, MIT.

A review of a codebase's overall structure, including how data moves, how parts depend on one another, and where failures or slowdowns may occur.

In plain words
What is it for?
Use it to assess maintainability, scalability, state ownership, data flow, error handling, and the boundaries between application layers.
Why use it?
It helps find design problems such as tightly connected modules, repeated database work, inconsistent error handling, and bottlenecks before they cause production incidents.

Skill for Claude Code

Written for Claude Code: allowed-tools in frontmatter.

Good fit Use it to assess maintainability, scalability, state ownership, data flow, error handling, and the boundaries between application layers.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/on-deck-society/love-stack/system-designer-review
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.

Any agent
npx skills add on-deck-society/love-stack --skill system-designer-review
Clone the repo
git clone --depth 1 https://github.com/on-deck-society/love-stack

Made for: Claude Code.

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 system-designer-review

README.md
[![agentmods](https://agentmods.dev/badge/skills/on-deck-society/love-stack/system-designer-review/github.svg)](https://agentmods.dev/skills/on-deck-society/love-stack/system-designer-review)
Your own site
<a href="https://agentmods.dev/skills/on-deck-society/love-stack/system-designer-review"><img src="https://agentmods.dev/badge/skills/on-deck-society/love-stack/system-designer-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.

agentmods 80×15 button for system-designer-review

Your own site · 80×15
<a href="https://agentmods.dev/skills/on-deck-society/love-stack/system-designer-review"><img src="https://agentmods.dev/badge/skills/on-deck-society/love-stack/system-designer-review.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 39 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 550 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00039 $0.00550
Opus 5 $0.00019 $0.00275
Sonnet 5 $0.00008 $0.00110
Haiku 4.5 $0.00004 $0.00055

Measured 10d ago against content hash a832d8963bf5, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

system-designer-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 10d 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.

templates/skills/system-designer-review/SKILL.md · 43 lines

How it starts

The opening of the file, as written. The whole thing — 43 lines — stays where its author put it; the contents beside it link to each section on GitHub.

System Designer Review

When activated, perform a structural review of the codebase with a senior system designer's lens.

Review Dimensions

  1. Data flow: Trace how data moves between components, services, and storage. Flag places where data is fetched redundantly, transformed inconsistently, or persisted without a clear source of truth.

  2. Coupling and cohesion: Identify tight coupling between modules that should be independent. Flag god files, circular dependencies, and places where business logic leaks into presentation or persistence layers.

  3. Scalability bottlenecks: Look for operations that would degrade at 10x or 100x current load. N+1 queries, synchronous calls that should be async, missing pagination, unbounded list operations.

  4. Error handling consistency: Check whether errors are handled with a consistent pattern across the codebase. Flag silent failures, caught-and-ignored errors, and missing error boundaries.

  5. State management: Review how state is owned, updated, and shared. Flag duplicate sources of truth, prop drilling that should be context, and global state that should be local.

  6. Abstraction levels: Flag missing abstractions (repeated patterns that should be extracted) and over-abstractions (premature generalization that adds complexity without benefit).

  7. External dependencies: List third-party services the system depends on. For each, assess blast radius if that dependency fails and whether a fallback exists.

  8. Testability: Identify code that's hard to test due to structure (untestable side effects, hidden dependencies, private state that should be injected).

Output Format

Produce a markdown report structured as:

  • Executive summary (3-5 bullet points, the big stuff)
  • Findings by dimension (one section per dimension above, with specific file and line references)
  • Severity-ordered action list (Critical, High, Medium, Low, what to fix first)
  • Questions for the team (anything ambiguous that warrants a discussion before deciding)

Read the full file on GitHub · 43 lines

Files

What ships with it

1 file 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.

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. 10d ago First seen · 43 lines · 39 tokens per session scan A a832d8963bf5

Subscribe to this mod's changes

system-designer-review is a skill published in the GitHub repository on-deck-society/love-stack (5 stars, last pushed 4mo ago), licensed MIT. It adds 39 tokens to every session and 550 once invoked, about $0.0002 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.