key-assumptions-check

key-assumptions-check is a skill for Claude Code from Liberty91LTD/cti-skills. It costs 49 tokens per session (657 once invoked), scanned A, original, MIT.

A method for listing and evaluating the assumptions behind an important analysis or judgment. It checks how much each assumption matters and how confident you are that it is valid.

In plain words
What is it for?
Use it before publishing a high-impact assessment or whenever you need to ask what an analysis is assuming and whether those assumptions still hold.
Why use it?
It makes hidden assumptions visible so you can see whether missing or incorrect information could change the conclusion.

Skill for Claude Code

Written for Claude Code: user-invocable in frontmatter.

Good fit Use it before publishing a high-impact assessment or whenever you need to ask what an analysis is assuming and whether those assumptions still hold.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/liberty91ltd/cti-skills/key-assumptions-check
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 Liberty91LTD/cti-skills --skill key-assumptions-check
Clone the repo
git clone --depth 1 https://github.com/Liberty91LTD/cti-skills

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 key-assumptions-check

README.md
[![agentmods](https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/key-assumptions-check/github.svg)](https://agentmods.dev/skills/liberty91ltd/cti-skills/key-assumptions-check)
Your own site
<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/key-assumptions-check"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/key-assumptions-check/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 key-assumptions-check

Your own site · 80×15
<a href="https://agentmods.dev/skills/liberty91ltd/cti-skills/key-assumptions-check"><img src="https://agentmods.dev/badge/skills/liberty91ltd/cti-skills/key-assumptions-check.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 49 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 657 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 $0.00049 $0.00657
Opus 5 $0.00024 $0.00329
Sonnet 5 $0.00010 $0.00131
Haiku 4.5 $0.00005 $0.00066

Measured 12d ago against content hash 442ae4158486, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-11, from the pricing page.

Security

Grade A, and why

key-assumptions-check 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 12d 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/key-assumptions-check/SKILL.md · 77 lines

How it starts

The opening of the file, as written. The whole thing — 77 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Key Assumptions Check

Every analytical judgment rests on assumptions — often unstated. This technique surfaces them and evaluates whether the analysis holds if assumptions are wrong.

Procedure

Step 1: State the Analytical Line

Write the current assessment or conclusion in one clear sentence.

Step 2: List All Assumptions

Brainstorm every assumption underlying the assessment. Include:

  • Assumptions about threat actor intent or capability
  • Assumptions about data completeness or accuracy
  • Assumptions about the relevance of historical patterns
  • Assumptions about the target environment
  • Assumptions about timing or sequencing

Step 3: Evaluate Each Assumption

Assumption Importance Confidence Status
[Assumption 1] High High Validated
[Assumption 2] High Low FLAG
[Assumption 3] Medium Medium Monitor
[Assumption 4] Low High Accepted

Importance: How much does the conclusion depend on this assumption?

  • High: If wrong, the conclusion changes significantly
  • Medium: If wrong, the conclusion weakens but may still hold
  • Low: If wrong, the conclusion is largely unaffected

Confidence: How sure are we this assumption is correct?

  • High: Strong evidence supports it
  • Medium: Some evidence, but not fully validated
  • Low: Little or no evidence; assumed by default

Step 4: Flag Critical Assumptions

Any assumption that is High Importance + Low Confidence is critical. These are the assumptions most likely to invalidate your analysis.

Step 5: Determine Impact

For each flagged assumption:

  • What would the conclusion be if this assumption is wrong?
  • Can this assumption be validated through additional collection?
  • Should the confidence level of the overall assessment be lowered?

Output Template

## Key Assumptions Check: [Assessment Title]

### Analytical Line
[The assessment being checked]

### Assumptions Matrix
| # | Assumption | Importance | Confidence | Status |
|---|-----------|:---:|:---:|:---:|
| 1 | ... | H/M/L | H/M/L | ... |

### Flagged Assumptions (High Importance + Low/Medium Confidence)
1. **[Assumption]**: If wrong, [impact on conclusion]. Collection gap: [what would validate this].

### Impact on Assessment
[Does the assumptions check change the confidence level? Should the conclusion be qualified?]

### Recommended Actions
- [Validate assumption X through Y collection]
- [Lower confidence from High to Moderate because of assumption Z]

Read the full file on GitHub · 77 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. 12d ago First seen · 77 lines · 49 tokens per session scan A 442ae4158486

Subscribe to this mod's changes

key-assumptions-check is a skill published in the GitHub repository Liberty91LTD/cti-skills (18 stars, last pushed 1mo ago), licensed MIT. It adds 49 tokens to every session and 657 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.