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.
git clone --depth 1 https://github.com/sean-sunagaku/claude-code-pluginWrote 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/plugins/sean-sunagaku/claude-code-plugin/subagent-best-practices)<a href="https://agentmods.dev/plugins/sean-sunagaku/claude-code-plugin/subagent-best-practices"><img src="https://agentmods.dev/badge/plugins/sean-sunagaku/claude-code-plugin/subagent-best-practices/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/plugins/sean-sunagaku/claude-code-plugin/subagent-best-practices"><img src="https://agentmods.dev/badge/plugins/sean-sunagaku/claude-code-plugin/subagent-best-practices.svg" alt="Reviewed on agentmods" width="80" height="20"></a>Grade A, and why
subagent-best-practices 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 2mo 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
{
"name": "subagent-best-practices",
"version": "1.0.0",
"description": " Claude Code の SubAgent（agents/*.md）を正しく定義するためのベストプラクティスガイド。 YAML frontmatter、ツール選択、3-Phase 構造、コンテキスト受け渡し、アンチパターンを網羅。 Use when: agents/*.md を書く、SubAgent 定義を改善する、エージェントの動作が想定外、 コンテキストが渡らない、ツール選択に迷う。 Triggers: \"subagent\", \"agent definition\", \"agents/*.md\", \"エージェント定義\", \"サブエージェント\", \"3-Phase\", \"context passing\", \"コンテキスト渡し\", \"tool selection\", \"ツール選択\", \"subagent_type\", \"bypassPermissions\"",
"author": {
"name": "sunagaku"
},
"license": "MIT",
"keywords": [
"subagent",
"best",
"practices"
]
}
What it installs
The manifest is a name and a version. 1 skill travel with it, and installing the plugin installs all of them — 185 tokens a session between them. Each is measured on its own page, and each can be installed alone.
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.
- 2mo ago First seen · 15 lines scan A fb1a95c919d3
subagent-best-practices is a plugin published in the GitHub repository sean-sunagaku/claude-code-plugin (38 stars, last pushed 3mo ago), licensed MIT. Its token cost is not measured: this kind of file is read by the harness, not the model. 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 2026-08-30.
subagent-best-practices compared with plugins from other repositories
| Mod | Type | Stars | Last push | Licence | Scan | Tokens | Works with |
|---|---|---|---|---|---|---|---|
| subagent-best-practicessean-sunagaku/claude-code-plugin | Plugin | 38 | 3mo ago | MIT | A | — | Claude Code |
| humanizerblader/humanizer | Plugin | 67k | 12d ago | MIT | A | — | Claude Code |
| claude-plugins-official marketplaceanthropics/claude-plugins-official | Plugin | 47k | today | Apache-2.0 | A | — | Claude Code |
| nextjsvercel/next.js | Plugin | 143k | yesterday | MIT | A | — | Claude Code |
| themes-examplegoogle-gemini/gemini-cli | Plugin | 109k | today | Apache-2.0 | A | — | Gemini CLI |
| knowledge-work-plugins marketplaceanthropics/knowledge-work-plugins | Plugin | 35k | 2d ago | Apache-2.0 | A | — | Claude Code |
| code-modernizationanthropics/claude-plugins-official | Plugin | 47k | today | Apache-2.0 | A | — | Claude Code |