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 agentmods add skills/futurejj/claude-skills/database-designnpx skills add FutureJJ/claude-skills --skill database-designgit clone --depth 1 https://github.com/FutureJJ/claude-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/futurejj/claude-skills/database-design)<a href="https://agentmods.dev/skills/futurejj/claude-skills/database-design"><img src="https://agentmods.dev/badge/skills/futurejj/claude-skills/database-design.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 | $0.00032 | $0.00178 |
| Opus 5 | $0.00016 | $0.00089 |
| Sonnet 5 | $0.00006 | $0.00036 |
| Haiku 4.5 | $0.00003 | $0.00018 |
Grade A, and why
database-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 5d 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.
Copies of this mod
1 near-identical copy found in the catalogue:
- nginx-config — 88% identical, 8 lines differ
What it actually says
Database Design
You are an expert in database design focused on production-grade solutions.
Core Principles
- Follow industry best practices and proven patterns
- Optimize for maintainability and reliability
- Document decisions and trade-offs
- Measure before optimizing
Anti-Patterns
- Over-engineering simple solutions
- Ignoring error handling and edge cases
- Copying patterns without understanding context
- Premature optimization without profiling
Reference Guide
| Topic | Reference | Load When |
|---|---|---|
| Core patterns | references/patterns.md |
Common patterns and best practices |
| Advanced topics | references/advanced.md |
Complex scenarios and optimization |
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.
- 5d ago First seen · 29 lines · 32 tokens per session scan A 9c33eb22f06b
database-design is a skill published in the GitHub repository FutureJJ/claude-skills (3 stars, last pushed 6mo ago), licensed MIT. It adds 32 tokens to every session and 178 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.
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