assumption-inventory

assumption-inventory is a skill for Claude Code, Codex from fzfclee/consulting-skills. It costs 50 tokens per session (766 once invoked), scanned A, original, Apache-2.0.

A method for listing the unproven beliefs behind a plan, recommendation, or diagnosis.

In plain words
What is it for?
It is for recording assumptions, risks, missing information, and validation actions before committing to a plan.
Why use it?
It helps reveal what could make a decision fail and shows which uncertain points should be checked first.

Skill for Claude CodeCodex

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

Good fit It is for recording assumptions, risks, missing information, and validation actions before committing to a plan.

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Install with agentmods
npx agentmods add skills/fzfclee/consulting-skills/assumption-inventory
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 fzfclee/consulting-skills --skill assumption-inventory
Clone the repo
git clone --depth 1 https://github.com/fzfclee/consulting-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 assumption-inventory

README.md
[![agentmods](https://agentmods.dev/badge/skills/fzfclee/consulting-skills/assumption-inventory/github.svg)](https://agentmods.dev/skills/fzfclee/consulting-skills/assumption-inventory)
Your own site
<a href="https://agentmods.dev/skills/fzfclee/consulting-skills/assumption-inventory"><img src="https://agentmods.dev/badge/skills/fzfclee/consulting-skills/assumption-inventory/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 assumption-inventory

Your own site · 80×15
<a href="https://agentmods.dev/skills/fzfclee/consulting-skills/assumption-inventory"><img src="https://agentmods.dev/badge/skills/fzfclee/consulting-skills/assumption-inventory.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 50 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 766 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 $0.00050 $0.00766
Opus 5 $0.00025 $0.00383
Sonnet 5 $0.00010 $0.00153
Haiku 4.5 $0.00005 $0.00077

Measured 10d ago against content hash 45c531e57a57, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-10, from the pricing page.

Security

Grade A, and why

assumption-inventory 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 10d 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/assumption-inventory/SKILL.md · 80 lines

How it starts

The opening of the file, as written. The whole thing — 80 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Assumption Inventory

Use this skill to expose the assumptions underneath a diagnosis or plan and decide which ones need testing first.

Method Notes

  • An assumption is something the plan relies on but has not yet proven.
  • Not all assumptions require immediate testing. Prioritize assumptions by impact if wrong and uncertainty.
  • This skill is useful before investing effort, making stakeholder moves, or committing to a strategy.

Required Inputs

Collect or infer these inputs before execution:

  • current diagnosis, plan, or recommendation
  • intended outcome
  • key stakeholders or users
  • known facts and constraints
  • major risks if the plan is wrong

If an input is missing, mark it as missing, state the assumption used, and add a validation action.

When Not To Use

Do not use when the issue is primarily role ownership, numerical prioritization, or root cause analysis. Use raci-matrix, wsjf-prioritization, or five-whys-root-cause instead.

Step-by-Step Execution

Step Required input How to execute Output
State the plan or diagnosis Current recommendation, target outcome. Write the conclusion in one plain sentence. Plan / diagnosis statement.
Extract assumptions Plan components, stakeholder beliefs, constraints, evidence gaps. Ask what must be true for this plan to work. Assumption list.
Classify assumptions Assumption list. Label each as market, customer, stakeholder, capability, resource, timing, risk, economics, or compliance. Classified assumptions.
Rate criticality Impact if wrong, uncertainty, reversibility. Score impact and uncertainty as high / medium / low. Mark whether the assumption is reversible. Critical assumption table.
Prioritize tests Critical assumptions, available access, deadline. Select the few assumptions that must be tested before action. Test priority list.
Define evidence needed Assumption, test method, success criteria. State what evidence would confirm, weaken, or disprove the assumption. Assumption test plan.

Read the full file on GitHub · 80 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. 10d ago First seen · 80 lines · 50 tokens per session scan A 45c531e57a57

Subscribe to this mod's changes

assumption-inventory is a skill published in the GitHub repository fzfclee/consulting-skills (4 stars, last pushed 22d ago), licensed Apache-2.0. It adds 50 tokens to every session and 766 once invoked, about $0.0003 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.