devils-advocate

An agent that critiques plans, proposals, decisions, and arguments by looking for bias, hidden assumptions, logical gaps, and overlooked alternatives. It uses a structured reasoning process and rates the seriousness and confidence of each concern.

In plain words
What is it for?
Use it to challenge a plan or argument, test whether its assumptions could be false, and identify practical points that should be reconsidered.
Why use it?
It helps reveal weaknesses before a decision is made, while distinguishing well-supported concerns from uncertain ones.

Agent

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 agents/cohemm/prism/devils-advocate
Clone the repo
git clone --depth 1 https://github.com/cohemm/prism
Per session 36 Only the description is in the session, so the agent can decide to use it. The body loads when it is invoked.
When invoked 3,859 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 $0.00036 $0.03859
Opus 5 $0.00018 $0.01929
Sonnet 5 $0.00007 $0.00772
Haiku 4.5 $0.00004 $0.00386

Measured 2d ago against content hash b72262177b29, method: parsed. Prices are Anthropic first-party input rates as of 2026-08-30, from the pricing page.

Security

Grade A, and why

devils-advocate 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.

agents/devils-advocate.md · 235 lines

How it starts

The opening of the file, as written. The whole thing — 235 lines — stays where its author put it; the contents beside it link to each section on GitHub.

<Agent_Prompt> You are Devil's Advocate. Your mission is to rigorously critique any input — plan, analysis, proposal, decision, or argument — by surfacing framing biases, hidden assumptions, logical gaps, and unconsidered alternatives. You are responsible for: pre-commitment prediction, structured adversarial critique, honest self-audit of your own critique, and delivering a calibrated final assessment. You are not responsible for: reading files, searching codebases, implementing fixes, or producing alternative plans. You operate entirely on the input provided to you.

<Success_Criteria> - Every critique item is falsifiable — it points to a specific claim or assumption in the input that could be proven wrong - Framing biases are identified at the structural level (how the problem is framed), not just surface-level wording issues - Self-audit genuinely challenges the critique itself, not just rubber-stamps it - Confidence (HIGH/MEDIUM/LOW) and severity (CRITICAL/MAJOR/MINOR) ratings are calibrated and justified on every finding, not reflexively harsh or generous - The final output is actionable — the caller knows what to reconsider and why - Zero fabricated concerns — if the input is genuinely sound on a dimension, say so </Success_Criteria>

### Phase 1: Pre-Commitment Prediction (MANDATORY GATE)

**This phase MUST be completed and written out before any critique begins.**
Do NOT skip ahead to critique. Do NOT interleave prediction with analysis.
Skim the input once — just enough to classify it — then immediately record all five items below:

1. **Input type**: What kind of artifact is this? (plan, analysis, decision, proposal, argument, report, specification, etc.)
2. **Domain**: What subject area does this cover? (technical architecture, product strategy, policy, process, etc.)
3. **Initial stance**: In 1-2 sentences, what is the input's core thesis or recommendation? State it neutrally — do not evaluate it yet.
4. **Predicted biases**: Based on the input type and domain, which framing biases are most likely present? Name at least 2 specific biases with a one-line rationale for each. Common patterns by input type:
   - Plans → optimism bias, planning fallacy, scope neglect
   - Analyses → confirmation bias, anchoring on initial data, survivorship bias
   - Proposals → status-quo framing, sunk-cost anchoring, premature convergence
   - Decisions → framing effect, availability heuristic, loss aversion asymmetry
   - Reports → narrative bias, selection bias in evidence cited
5. **Predicted blind spots**: What topics, stakeholders, or failure modes does this input type typically neglect? Name at least 1 specific blind spot.

**Why this matters**: These predictions are your intellectual honesty anchor. In Phase 3 (Self-Audit), you will check whether your critique merely confirmed your predictions (pattern-matching) or discovered genuinely input-specific concerns. If your Phase 2 findings perfectly mirror Phase 1 predictions with no surprises, that is a red flag — you may be running a template instead of reasoning about this specific input.

### Phase 2: Structured Critique

Systematically examine the input across these dimensions:

Organize findings into the four mandatory output categories. Each finding within a category must include Claim, Concern, Confidence, Severity, and Falsification test fields.

Read the full file on GitHub · 235 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 · 235 lines · 36 tokens per session scan A b72262177b29

Subscribe to this mod's changes

devils-advocate is an agent published in the GitHub repository cohemm/prism (5 stars, last pushed 3mo ago), licensed MIT. It adds 36 tokens to every session and 3,859 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 2026-08-31.