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 atstaeff/ai-agents --skill system-designgit clone --depth 1 https://github.com/atstaeff/ai-agentsWrote 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/atstaeff/ai-agents/system-design)<a href="https://agentmods.dev/skills/atstaeff/ai-agents/system-design"><img src="https://agentmods.dev/badge/skills/atstaeff/ai-agents/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/atstaeff/ai-agents/system-design"><img src="https://agentmods.dev/badge/skills/atstaeff/ai-agents/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 | $0.00021 | $0.00129 |
| Opus 5.5 | $0.00008 | $0.00052 |
| Sonnet 5.5 | $0.00004 | $0.00026 |
| Haiku 4.5 | $0.00002 | $0.00013 |
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 12d 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.
What it actually says
System Design
Workflow
- Establish use cases, scale, data lifecycle and quality requirements before choosing components.
- Use architecture-planning for a compact option comparison and decision.
- Keep topology as simple as the needs allow and verify the riskiest assumption.
Completion
Return the concrete result, verification evidence and any material unresolved limitation. Keep documentation proportional to the change and preserve human feedback.
Select a focused topic
What ships with it
2 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.
- 12d ago Changed · +1 lines · +3 tokens per session 4cf21ad453da
- 1mo ago First seen · 20 lines · 18 tokens per session scan A c3e547fa08a3
system-design is a skill published in the GitHub repository atstaeff/ai-agents (3 stars, last pushed 10d ago), licensed MIT. It adds 21 tokens to every session and 129 once invoked, about $0.0001 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 2026-08-31.
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