expert-munger

expert-munger is a skill for Claude Code, Codex from AskRoundtable/expert-skills. It costs 41 tokens per session (2,713 once invoked), scanned A, original, MIT.

A decision guide based on Charlie Munger’s mental models for investments, businesses, incentives, and avoiding mistakes. It emphasizes looking at problems from the opposite direction and examining key assumptions.

In plain words
What is it for?
Use it to assess investments, business strategies, deals, incentive structures, and decisions that need perspectives from more than one field.
Why use it?
It helps expose hidden assumptions, misleading incentives, and risks outside the decision-maker’s expertise. This can make business and investment reasoning more systematic.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one.

Good fit Use it to assess investments, business strategies, deals, incentive structures, and decisions that need perspectives from more than one field.

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Install with agentmods
npx agentmods add skills/askroundtable/expert-skills/expert-munger
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.

Any agent
npx skills add AskRoundtable/expert-skills --skill expert-munger
Clone the repo
git clone --depth 1 https://github.com/AskRoundtable/expert-skills

Made for: Claude Code, Codex.

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 expert-munger

README.md
[![agentmods](https://agentmods.dev/badge/skills/askroundtable/expert-skills/expert-munger.svg)](https://agentmods.dev/skills/askroundtable/expert-skills/expert-munger)
Your own site
<a href="https://agentmods.dev/skills/askroundtable/expert-skills/expert-munger"><img src="https://agentmods.dev/badge/skills/askroundtable/expert-skills/expert-munger.svg" alt="Measured on agentmods" height="20"></a>
Per session 41 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 2,713 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 $0.00041 $0.02713
Opus 5 $0.00020 $0.01357
Sonnet 5 $0.00008 $0.00543
Haiku 4.5 $0.00004 $0.00271

Measured 7d ago against content hash 062d3d79acec, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-07, from the pricing page.

Security

Grade A, and why

expert-munger 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.

skills/expert-munger/SKILL.md · 291 lines

How it starts

The opening of the file, as written. The whole thing — 291 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Expert Module: Charlie Munger

Encodes Charlie Munger's thinking patterns for use with expert-engine.

When to Load

Load this module when analyzing:

  • Investment decisions
  • Business strategy
  • Avoiding costly mistakes
  • Incentive structures
  • Any decision requiring multi-disciplinary thinking

Problem Framing (What → Why):

What-layer questions that arrive here often:

  • "Analyze this investment for me" → Why-layer: "What's the one assumption that, if wrong, makes this a bad decision?"
  • "Should I do X or Y?" → Why-layer: "What am I optimizing for—and is that my real objective function?"
  • "What do you think of this deal?" → Why-layer: "Where am I outside my circle of competence?"

When the user presents a What question, ask:

"Invert first: if this decision turned out to be a disaster in 5 years, what would be the most likely reason? That's the assumption we need to examine."

Domain Boundaries

Core Domain (High Confidence): Munger's frameworks work best for decisions involving capital allocation, business evaluation, and avoiding cognitive biases. Use with full confidence.

  • Investment analysis (stocks, businesses, assets)
  • Business strategy and competitive dynamics
  • Evaluating management and incentive structures
  • Identifying cognitive biases in decision-making

Extended Domain (Moderate Confidence): The mental models (Inversion, Second-Order Thinking, etc.) are general-purpose and can assist with broader decisions. Use the frameworks, but acknowledge they weren't designed for these contexts.

  • Career decisions
  • Personal finance
  • Negotiation and deal-making
  • Any decision with trade-offs and opportunity costs

Outside Domain (Low Confidence): For these areas, acknowledge limitations upfront. Provide general thinking frameworks only, not domain expertise.

  • Technical/engineering decisions
  • Creative/artistic judgments
  • Relationship/emotional decisions (framework is rational)
  • Domains requiring specialized knowledge (medicine, law, etc.)

Read the full file on GitHub · 291 lines

Files

What ships with it

9 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.

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. 7d ago First seen · 291 lines · 41 tokens per session scan A 062d3d79acec

Subscribe to this mod's changes

expert-munger is a skill published in the GitHub repository AskRoundtable/expert-skills (51 stars, last pushed 5mo ago), licensed MIT. It adds 41 tokens to every session and 2,713 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 2026-08-30.

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