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 HoangNguyen0403/agent-skills-standard --skill database-mongodbgit clone --depth 1 https://github.com/HoangNguyen0403/agent-skills-standardWrote 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/hoangnguyen0403/agent-skills-standard/database-mongodb)<a href="https://agentmods.dev/skills/hoangnguyen0403/agent-skills-standard/database-mongodb"><img src="https://agentmods.dev/badge/skills/hoangnguyen0403/agent-skills-standard/database-mongodb/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/hoangnguyen0403/agent-skills-standard/database-mongodb"><img src="https://agentmods.dev/badge/skills/hoangnguyen0403/agent-skills-standard/database-mongodb.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
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 | $0.00037 | $0.00405 |
| Opus 5 | $0.00018 | $0.00202 |
| Sonnet 5 | $0.00007 | $0.00081 |
| Haiku 4.5 | $0.00004 | $0.00040 |
Grade A, and why
database-mongodb 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 9d 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
MongoDB Best Practices
Priority: P0 (CRITICAL)
Rules
- Model from access patterns: data read together should usually live together.
- Embed for bounded one-to-few data; reference for unbounded growth or independent lifecycle.
- Build indexes for real queries, not theoretical flexibility. Use ESR ordering for equality -> sort -> range compound indexes.
- Use transactions only when single-document guarantees are insufficient.
Verify
- Embed vs reference choice matches cardinality and lifecycle.
- Compound index order matches equality -> sort -> range access.
- Large pagination uses cursor patterns, not deep
skip(). - Explain output supports the chosen indexes; review
keysExaminedanddocsExamined. - Unbounded arrays and hot shard keys were reviewed.
Anti-Patterns
- No unbounded arrays: Use
$pushwith$sliceor redesign using Bucket Pattern. - No client-side filtering: Project only needed fields; never fetch full docs to filter in memory.
- No deep nesting: Keep nesting ≤4 levels; flatten paths that frequently queried.
- No index cargo cult: each index must map to a read path and write tradeoff.
References
What ships with it
6 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.
- 9d ago First seen · 49 lines · 37 tokens per session scan A 6b9b43fdaef0
database-mongodb is a skill published in the GitHub repository HoangNguyen0403/agent-skills-standard (565 stars, last pushed 3d ago), licensed MIT. It adds 37 tokens to every session and 405 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 2026-09-03.
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