challenge

A two-phase decision check for testing whether a problem is real and whether a proposed idea is useful. It examines evidence, asks about only high-impact irreversible choices, and ends with a GO or NO-GO decision.

In plain words
What is it for?
Use it to assess a proposal, review its evidence, identify important trade-offs, and decide whether to proceed. It is not intended for code-review findings.
Why use it?
It reduces the risk of building on an unverified problem or weak proposal. It also makes unresolved assumptions visible before work starts.

Skill for Claude CodeCodex

Install

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.

agentmods
npx agentmods add skills/thkt/dotclaude/challenge
Any agent
npx skills add thkt/dotclaude --skill challenge
Clone the repo
git clone --depth 1 https://github.com/thkt/dotclaude

Made for: Claude Code, Codex.

Per session 204 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 1,758 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. Scan, not verified.
Origin original No closer match found in the catalogue.
Token cost

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.

ModelPer sessionOnce invoked
Fable 5 $0.00204 $0.01758
Opus 5 $0.00102 $0.00879
Sonnet 5 $0.00041 $0.00352
Haiku 4.5 $0.00020 $0.00176

Measured 2d ago against content hash 943f99b91a46, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

challenge 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 2d 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.

.ja/skills/challenge/SKILL.md · 85 lines

How it starts

The opening of the file, as written. The whole thing — 85 lines — stays where its author put it; the contents beside it link to each section on GitHub.

/challenge - 提案の GO / NO-GO 判定

提案を 2 フェーズで判定し、次の意思決定を検証済みの GO/NO-GO から始めさせる。

入力

$ARGUMENTS に対象を受け取る。提案のファイルパスか、記述そのものを渡す。空なら停止して対象の指定をユーザーに求め、会話から推測しない。複数行のときは先頭行が対象のタイトル。

Phase 1: Grill

提案を証拠で検証し、決着しなかった論点だけをユーザーへ返す。

Step 1: 論点を証拠で決着させる

判断はすべて下表が定める。advisor の自信度では決めない。

対象 条件 満たすときの扱い 満たさないときの扱い
論点 証拠で答えが 1 つに決まる。優先順位やスコープのように選択が要るものは決まらない subagent が並列で答えを確かめる 検証せず未決へ回す
確かめた事実 狙う状態が既に成立している、または提案と矛盾する。advisor の見解だけでは満たさない Phase 2 を飛ばし、根拠を Why に据える 食い違わなかった主張で続ける
未決の論点 後戻りできない、または影響が大きい AskUserQuestion で聞く。上限 7 問 advisor の仮説を仮定として進め、Why に全件残す
  1. .claude/OUTCOME.md を読む。無ければ $ARGUMENTS と会話から outcome を推定し、AskUserQuestion で確認する。Phase 2 の outcome 攻撃がこれを評価軸に使うので、省略せず確定させる
  2. 提案の論点を洗い出し、表に従って振り分ける
  3. 検証ループを回す。subagent が並列で答えを確かめ、advisor が振り分けを見直して次の証拠を指す
  4. 証拠を足しても振り分けが変わらなくなったら打ち切る。上限 3 周。決着しなかった論点は未決へ回す
  5. 確かめた事実を表に当てる。Phase 2 を飛ばす扱いなら、そのまま出力へ抜ける
  6. 未決の論点へ advisor が仮説、可逆性、影響度を付け、表に従って振り分ける

Step 2: 引き継ぎを作る

Step 1 の発見を下表の形に集約する。Phase 2 はこれだけを入力に取る。

項目 ソース
approach 提案が何をするかの 1 行要約
decisions 固まったアーキテクチャ水準の判断。用語確認やスコープ細部は除く
trade-offs 表面化したトレードオフ
referenced_files 参照したファイル
outcome_ref .claude/OUTCOME.md のパスと Behavior / Non-goals / Constraints の要約。無ければ Step 1 で確認した outcome

Read the full file on GitHub · 85 lines

Changes

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.

  1. 2d ago First seen · 85 lines · 204 tokens per session scan A 943f99b91a46

Subscribe to this mod's changes

challenge is a skill published in the GitHub repository thkt/dotclaude (11 stars, last pushed 3d ago), licensed MIT. It adds 204 tokens to every session and 1,758 once invoked, about $0.0010 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 2026-08-30.

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