critical-case-design

critical-case-design is a skill for Claude Code, Codex from yogsoth-ai/stress-test. It costs 29 tokens per session (581 once invoked), scanned A, original, Apache-2.0.

A research method for choosing cases that strongly test a claim: one where the claim should work, and one where it should be unlikely to work.

In plain words
What is it for?
Use it to define test cases, probe the limits of an argument, find counterexamples, and judge how strongly each result supports or challenges the claim.
Why use it?
It helps show whether a claim survives unusually favorable and unfavorable conditions, instead of relying on ordinary examples.

Skill for Claude CodeCodex

Written for no agent in particular: nothing here depends on one. Also seen: mentions subagents.

Good fit Use it to define test cases, probe the limits of an argument, find counterexamples, and judge how strongly each result supports or challenges the claim.

Compare 6 skills from other repositories ↓
Install with agentmods
npx agentmods add skills/yogsoth-ai/stress-test/critical-case-design
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 yogsoth-ai/stress-test --skill critical-case-design
Clone the repo
git clone --depth 1 https://github.com/yogsoth-ai/stress-test

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 critical-case-design

README.md
[![agentmods](https://agentmods.dev/badge/skills/yogsoth-ai/stress-test/critical-case-design/github.svg)](https://agentmods.dev/skills/yogsoth-ai/stress-test/critical-case-design)
Your own site
<a href="https://agentmods.dev/skills/yogsoth-ai/stress-test/critical-case-design"><img src="https://agentmods.dev/badge/skills/yogsoth-ai/stress-test/critical-case-design/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 critical-case-design

Your own site · 80×15
<a href="https://agentmods.dev/skills/yogsoth-ai/stress-test/critical-case-design"><img src="https://agentmods.dev/badge/skills/yogsoth-ai/stress-test/critical-case-design.svg" alt="Reviewed on agentmods" width="80" height="20"></a>
Per session 29 Skills are progressive disclosure: only the name and description are preloaded; the body loads when the skill is used.
When invoked 581 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 $0.00029 $0.00581
Opus 5 $0.00015 $0.00291
Sonnet 5 $0.00006 $0.00116
Haiku 4.5 $0.00003 $0.00058

Measured 9d ago against content hash 3337cd5b8ab1, method: parsed. Prices are Anthropic first-party input rates as of 2026-09-09, from the pricing page.

Security

Grade A, and why

critical-case-design 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.

skills/critical-case-design/SKILL.md · 78 lines

How it starts

The opening of the file, as written. The whole thing — 78 lines — stays where its author put it; the contents beside it link to each section on GitHub.

Critical Case Design

Tactics

  • boundary-probing
  • counterexample-heuristics

Method

  1. Identify the claim's scope and conditions
  2. Design most-likely case: conditions maximally favorable to claim
  3. Design least-likely case: conditions maximally unfavorable
  4. If claim fails in most-likely case: strong disconfirmation
  5. If claim holds in least-likely case: strong confirmation
  6. Report inferential power of each test

Budget

Size Critical cases designed Evaluation depth
S 2 (one most-likely, one least-likely) Surface
M 4 (two each) Moderate
L 6 (three each) Deep

Orchestration

  1. Dispatch parameter-space-mapping to identify conditions
  2. Dispatch extreme-value-generation for favorable/unfavorable extremes
  3. Dispatch breakpoint-detection to test claim at critical cases
  4. Dispatch contradiction-detection to evaluate outcomes

Subagents

  • parameter-space-mapping
  • extreme-value-generation
  • breakpoint-detection
  • contradiction-detection

Available Tactics

Optional, no fixed order; the final leaf is always a sop.

Tactic When to use
boundary-probing Map parameter space, generate extreme values, test at boundaries, detect breakpoints, synthesize validity envelope.
counterexample-heuristics Generate counterexamples (monsters), attempt monster-barring, incorporate surviving counterexamples as lemma refinements (Lakatos method).

Available SOPs

Optional, no fixed order; the final leaf is always a sop.

SOP When to use
breakpoint-detection Test a claim at extreme parameter values and detect the precise point where it breaks down.
contradiction-detection Evaluate whether a derivation chain has reached a genuine contradiction, absurdity, or inconclusive state.
extreme-value-generation Generate boundary and extreme test values for a given parameter dimension to stress-test claims.
parameter-space-mapping Identify all parameter dimensions along which a claim's validity might vary.

Read the full file on GitHub · 78 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. 9d ago First seen · 78 lines · 29 tokens per session scan A 3337cd5b8ab1

Subscribe to this mod's changes

critical-case-design is a skill published in the GitHub repository yogsoth-ai/stress-test (2 stars, last pushed 2mo ago), licensed Apache-2.0. It adds 29 tokens to every session and 581 once invoked, about $0.0001 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.

Related

Other skills, from other repositories

tournament-judge

Runs a domain-neutral, evidence-based tournament in which independent candidates are reviewed, anonymized, and scored by a blind judge against a rubric fixed before judging. Use when comparing competing plans, designs, implementations, documents, tools, vendors, strategies, or other substantial options; when the user…

alextverdyy/tournament-judge · 105 tokens

sector-rotation

An analysis framework for comparing industries in the Chinese A-share stock market, using business conditions, price momentum, valuation, and money flows. It produces rankings and higher- or lower-allocation suggestions.

HKUDS/Vibe-Trading · 39 tokens

rework-rate

Measure and interpret PR rework rate — the emerging 5th DORA metric.

bradygaster/squad · 20 tokens

oma-scholar

Scholarly research companion using Knows sidecar spec (.knows.yaml). Generates, validates, reviews, queries, and compares structured research-paper sidecars, and fetches them from knows.academy. Use for academic literature search, survey synthesis, paper authoring assistance, and peer review with token-efficient…

first-fluke/oh-my-agent · 73 tokens

browser_cdp

A health check for Python code that produces a score, letter grade, and measures of issues such as complexity, duplication, dead code, dependencies, and architecture.

mateaix/mateclaw · 44 tokens

shogun-screenshot

A screenshot tool for getting images from a computer or web page and then cropping, resizing, or masking sensitive information. Playwright is a browser-automation tool used here to capture web pages.

yohey-w/multi-agent-shogun · 149 tokens