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 s977043/river-review --skill capacity-cost-designgit clone --depth 1 https://github.com/s977043/river-reviewWrote 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/s977043/river-review/capacity-cost-design)<a href="https://agentmods.dev/skills/s977043/river-review/capacity-cost-design"><img src="https://agentmods.dev/badge/skills/s977043/river-review/capacity-cost-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/s977043/river-review/capacity-cost-design"><img src="https://agentmods.dev/badge/skills/s977043/river-review/capacity-cost-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 | $0.00030 | $0.01199 |
| Opus 5 | $0.00015 | $0.00600 |
| Sonnet 5 | $0.00006 | $0.00240 |
| Haiku 4.5 | $0.00003 | $0.00120 |
Grade A, and why
Capacity, Performance & Cost Assumptions 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 7d 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
Pattern declaration
Primary pattern: Reviewer Secondary patterns: Inversion Why: 性能・容量・コストの前提漏れをチェックリスト型で評価し、本番ではじめて発覚するリスクを低減する
Goal / 目的
- 設計の差分から、性能/容量/コストの前提不足により “本番で初めて詰む” リスクを減らす。
Non-goals / 扱わないこと
- 具体的なインフラ構成やクラウドサービスの最適解を断定しない。
- 実装レベルのチューニング（クエリ改善やキャッシュ実装など）。
Pre-execution Gate / 実行前ゲート
このスキルは以下の条件がすべて満たされない限りNO_REVIEWを返す。
- 差分に設計ドキュメント（設計書/ADR/容量計画書）の変更がある
- 差分に性能・容量・コストの前提や目標に関わる記述の追加または変更がある
- inputContextにdiffが含まれている
ゲート不成立時の出力: NO_REVIEW: capacity-cost-design — 性能・容量・コスト設計に関わる変更が検出されない
False-positive guards / 抑制条件
- PoC/運用対象外と明記されている場合は、必須要件としては扱わず “確認” に留める。
Rule / ルール
- 先頭に要約を 1 行出す（クリティカルパスと前提の変更点）。
- 指摘は最大 8 件まで。性能予算/上限制約/コスト爆発のリスクを優先。
- “追記テンプレ” を付けて、文書に落とせる形にする。
Checklist / 観点チェックリスト
- トラフィック前提
- 想定 QPS/ピーク、データ量、同時接続などの前提があるか。
- 増加率（成長）と期間の前提があるか。
- 性能予算（Budget）
- 重要フローのレイテンシ目標（p95/p99）と内訳があるか。
- タイムアウト/リトライで “増幅” しない前提になっているか。
- ボトルネックと限界
- 依存（外部 API/DB/キュー）の上限と、劣化時のふるまいがあるか。
- Backpressure（キュー溢れ、レート制限）と、落としどころがあるか。
- コスト
- コストドライバー（データ転送、ストレージ、ログ、外部 API 課金）が列挙されているか。
- コスト上限/監視/アラートの前提があるか。
Output / 出力フォーマット
すべて日本語。<file>:<line>: <message> 形式で出力する。
- 先頭に要約を 1 行:
(summary):1: <重要フローと前提/予算の要点> - 以降は指摘（最大 8 件）:
<message>に[severity=critical|major|minor|info]を含める。- 可能なら “追記テンプレ” を 1 行付ける。
追記テンプレ例:
前提: peakQPS=<>, payload=<>, dataGrowth=<>, 期間=<>性能: p95=<ms>, p99=<ms>, timeout=<ms>, retry=<回数>コスト: ドライバー=<>, 上限=<>, 監視=<メトリクス>
評価指標（Evaluation）
- 合格基準: 差分に紐づく前提/予算/上限の抜けが優先度付きで指摘され、追記案がある。
- 不合格基準: 推測の断定、差分と無関係な一般論、指摘過多。
人間に返す条件（Human Handoff）
- コスト上限や性能目標がビジネス判断に跨る場合は人間（PM/Tech Lead）へ返す。
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.
- 7d ago First seen · 99 lines · 30 tokens per session scan A 8ca9388b37a2
Capacity, Performance & Cost Assumptions is a skill published in the GitHub repository s977043/river-review (3 stars, last pushed today), licensed MIT. It adds 30 tokens to every session and 1,199 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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