skeptic

skeptic is an agent for Claude Code from curtischoutw/claude-institution. It costs 71 tokens per session (664 once invoked), scanned A, original, MIT.

A review agent that tries to disprove a claim, conclusion, or code change. It checks assumptions, uses repository tools and commands, and reports whether the claim survived its scrutiny.

In plain words
What is it for?
Use it for correctness reviews of major conclusions or code changes, with findings tied to files, line numbers, or repeatable checks.
Why use it?
It helps expose untested assumptions, logical gaps, and counterexamples before relying on an important result.

Agent for Claude Code

Written for Claude Code: a Claude Code subagent (agents/*.md). Also seen: reads .claude/ paths; mentions subagents.

Good fit Use it for correctness reviews of major conclusions or code changes, with findings tied to files, line numbers, or repeatable checks.

Compare 6 agents from other repositories ↓
Install with agentmods
npx agentmods add agents/curtischoutw/claude-institution/skeptic
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.

Clone the repo
git clone --depth 1 https://github.com/curtischoutw/claude-institution

Made for: Claude Code.

Wrote 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.

agentmods badge for skeptic

README.md
[![agentmods](https://agentmods.dev/badge/agents/curtischoutw/claude-institution/skeptic/github.svg)](https://agentmods.dev/agents/curtischoutw/claude-institution/skeptic)
Your own site
<a href="https://agentmods.dev/agents/curtischoutw/claude-institution/skeptic"><img src="https://agentmods.dev/badge/agents/curtischoutw/claude-institution/skeptic/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.

agentmods 80×15 button for skeptic

Your own site · 80×15
<a href="https://agentmods.dev/agents/curtischoutw/claude-institution/skeptic"><img src="https://agentmods.dev/badge/agents/curtischoutw/claude-institution/skeptic.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 71 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 664 The whole file, excluding the scripts and references it only reads on demand.
Security scan A 0 findings. A grade says what 26 rules found in the file — not that it is safe.
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 5.1 $0.00071 $0.00664
Opus 5 $0.00036 $0.00332
Sonnet 5 $0.00014 $0.00133
Haiku 4.5 $0.00007 $0.00066

Measured 9d ago against content hash 4c0d3789786b, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

skeptic 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.

institution/agents/skeptic.md · 38 lines

What it actually says

你是對抗審查小組裡的「正確性」鏡頭。任務不是幫忙,是盡全力推翻你收到的主張、 結論或程式碼變更。預設立場:這個東西是錯的,你的工作是找出哪裡錯,找不到才算過。

取材自 Miguok/fable-harness 的 skeptic subagent 設計,綁回本專案自己的判準: ~/.claude/rules-lib/uplift.md 方法 2(多答案評審擇優)與方法 3(對抗自查/紅隊回合)、 ~/.claude/rules-lib/judgment.md 方法 5(品質底線的 fresh-context 驗證)。

你要做什麼

  1. 列出所有假設:主張裡明說的、以及沒明說但被默默依賴的假設,一條都不放過。
  2. 用工具實證,不准憑推理:呼叫 Read/Grep/Glob 去讀實際程式碼與資料,用 Bash 實際跑指令驗證。禁止「理論上應該沒問題」這種話——沒跑過就不算查過。
  3. 建反例:針對每個假設,試著構造一個會讓它破裂的具體輸入/狀態/時序。
  4. 查不到就明說「不確定」,不要用肯定語氣包裝猜測(同 hard-rules.md #8)。

何時判 SURVIVED

只有在你已經照上面步驟 1–3 認真嘗試推翻(列了假設、用工具實證、試著建反例)、 仍然找不到任何站得住的反例時,才判 SURVIVED。「看起來合理」不是 SURVIVED 的理由, 但也不能為了判 REFUTED 而編造牽強的反例——找不到就誠實判 SURVIVED。

輸出格式(必須是這個 YAML 信封)

verdict: REFUTED | SURVIVED
confidence: high | medium | low
reasons:
  - "<具體理由,附 檔案:行號 或可重現的步驟>"
untested_assumptions:
  - "<你沒能力驗證、但主張依賴的假設,誠實列出>"
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. 9d ago First seen · 38 lines · 71 tokens per session scan A 4c0d3789786b

Subscribe to this mod's changes

skeptic is an agent published in the GitHub repository curtischoutw/claude-institution (5 stars, last pushed 8d ago), licensed MIT. It adds 71 tokens to every session and 664 once invoked, about $0.0004 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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