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 sun2443/designer-skills --skill system-designgit clone --depth 1 https://github.com/sun2443/designer-skillsWrote 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/sun2443/designer-skills/system-design)<a href="https://agentmods.dev/skills/sun2443/designer-skills/system-design"><img src="https://agentmods.dev/badge/skills/sun2443/designer-skills/system-design/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/sun2443/designer-skills/system-design"><img src="https://agentmods.dev/badge/skills/sun2443/designer-skills/system-design.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 | $0.00055 | $0.00283 |
| Opus 5.5 | $0.00022 | $0.00113 |
| Sonnet 5.5 | $0.00011 | $0.00057 |
| Haiku 4.5 | $0.00006 | $0.00028 |
Grade A, and why
system-design 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 13d 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.
This is a copy
100% identical to system-design — 0 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
What it actually says
System Design
Help design systems and evaluate architectural decisions.
Framework
1. Requirements Gathering
- Functional requirements (what it does)
- Non-functional requirements (scale, latency, availability, cost)
- Constraints (team size, timeline, existing tech stack)
2. High-Level Design
- Component diagram
- Data flow
- API contracts
- Storage choices
3. Deep Dive
- Data model design
- API endpoint design (REST, GraphQL, gRPC)
- Caching strategy
- Queue/event design
- Error handling and retry logic
4. Scale and Reliability
- Load estimation
- Horizontal vs. vertical scaling
- Failover and redundancy
- Monitoring and alerting
5. Trade-off Analysis
- Every decision has trade-offs. Make them explicit.
- Consider: complexity, cost, team familiarity, time to market, maintainability
Output
Produce clear, structured design documents with diagrams (ASCII or described), explicit assumptions, and trade-off analysis. Always identify what you'd revisit as the system grows.
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.
- 13d ago First seen · 43 lines · 55 tokens per session scan A 8f28eca99f22
system-design is a skill published in the GitHub repository sun2443/designer-skills (0 stars, last pushed 6mo ago), licensed Apache-2.0. It adds 55 tokens to every session and 283 once invoked, about $0.0002 per session on Opus 5.5. A static security scan graded it A with 0 findings. It is 100% identical to system-design, differing in 0 lines, and is treated as a copy.
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