Borrowing it
Nothing to install: this file belongs to sei-newbear/xp-harness. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/sei-newbear/xp-harness/main/.claude/skills/skill-design-style/SKILL.mdgit clone --depth 1 https://github.com/sei-newbear/xp-harnessWrote 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/sei-newbear/xp-harness/skill-design-style)<a href="https://agentmods.dev/skills/sei-newbear/xp-harness/skill-design-style"><img src="https://agentmods.dev/badge/skills/sei-newbear/xp-harness/skill-design-style.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 | $0.00070 | $0.07189 |
| Opus 5 | $0.00035 | $0.03594 |
| Sonnet 5 | $0.00014 | $0.01438 |
| Haiku 4.5 | $0.00007 | $0.00719 |
Grade A, and why
skill-design-style 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 8d 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.
How it starts
The opening of the file, as written. The whole thing — 250 lines — stays where its author put it; the contents beside it link to each section on GitHub.
skill 設計の流儀 — skill / agent の新規作成・改修時の流儀
なぜこの skill があるか
xp-harness の harness 機構 (= skill / agent / CLAUDE.md) を改修者が改修するとき、規律 / 判断軸 / 改修フローが散在していると、改修者 (main session) が機械的処理に流れて失敗する。本 skill は改修者向けの規律 / 判断軸 / 改修フローを単一の出典 (= single source) として集約する。
中核哲学 (= 改修者の方向性)
依頼者の真のゴール: 自走
改修者が「やりたいこと」を伝えたら、main session (コーディング Agent) が harness 機構に適切に落とし込めるよう、ある程度自走して任せられる状態を実現する。本 skill はその自走を支える規律集。
「依頼者から都度説明を受けないと整理できない」状態を解消し、.apm/ 配下 (= 利用者向け本題) の改修を進められる状態にする。
xp-harness の中核思想
- 規律装置最小注入: 規律は最小限の文書で注入する。重複させない、肥大化させない
- ペアプロ哲学: 機械的なチェックよりも subagent / 改修者によるペアプロでの捕捉が筋
- 単一責任 (= SRP): 各 skill / agent / instruction は単一の責任を持つ
harness 機構の E2E テスト枠組みは未確立
skill / CLAUDE.md / subagent の harness 機構には E2E テスト枠組みが未確立。改修の Done は事前縛りを最小化し、事後評価を許容する。投資フェーズの仕組み作りでは、運用コスト最適化より価値命題の充実を優先する。
subagent はペアプロ的な第三者として 3 用途
reviewer 系の subagent (code-reviewer / e2e-reviewer / pre-implementation-reviewer / done-verifier / skill-reviewer) は、強制 gate ではなくペアプロの相手としての第三者:
- 改修後の最終レビュー (= 必須)
- 設計中の壁打ち / 議論 (= 任意・対話的、何度でも)
- 判断に迷ったときの第三者視点 (= 任意、依頼者に確認する前のステップとして気軽に呼ぶ)
スコープ境界の判別 (= 利用者向け vs 改修者向け)
xp-harness は OSS として skill / agent / instruction を配布する harness。改修対象が「利用者向け」か「改修者向け」かを必ず判別する。
| カテゴリ | パス | 配布 | 改修方針 |
|---|---|---|---|
| 利用者向け | .apm/skills/* / .apm/agents/* / .apm/instructions/* および .claude/ 配下の対応 symlink (= .apm/ と同じ実体) |
APM 経由で配布 | 慎重に、scope 外なら触らない |
| 改修者向け | CLAUDE.md (project root) / .claude/skills/philosophy/ / .claude/skills/release/ / .claude/skills/skill-design-style/ / .claude/agents/skill-reviewer.md (それぞれ git tracked、symlink でない) |
非配布 | philosophy skill と同じパターン、.claude/ 配下に直接コミット |
判別法: ls -la で symlink でないことを確認。symlink なら .apm/ 配下と同じものなので利用者向け、symlink でなく直接コミットされていれば改修者向け。
新規 skill / agent を改修者向けで作るときは、必ず .claude/ 配下に直接コミット (= .apm/ には置かない)。
skill 改修フロー (= 改修者が読んで自走する手順)
skill / agent を新規作成・改修するときは、以下の手順を順に通す。
手順 1: 何を / どこに書くか判断 (= 4 軸で位置づける)
skill / description / 本文 / 要件定義.md / 他 skill / CLAUDE.md のどこに書くべきか、以下 4 軸で位置づける:
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.
- 8d ago First seen · 250 lines · 70 tokens per session scan A 3e3599894882
skill-design-style is a skill published in the GitHub repository sei-newbear/xp-harness (9 stars, last pushed 1mo ago), licensed MIT. It adds 70 tokens to every session and 7,189 once invoked, about $0.0003 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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