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.
npx skills add frank-luongt/faos-skills-marketplace --skill ab-test-setupgit clone --depth 1 https://github.com/frank-luongt/faos-skills-marketplaceWrote 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.
[](https://agentmods.dev/skills/frank-luongt/faos-skills-marketplace/ab-test-setup)<a href="https://agentmods.dev/skills/frank-luongt/faos-skills-marketplace/ab-test-setup"><img src="https://agentmods.dev/badge/skills/frank-luongt/faos-skills-marketplace/ab-test-setup/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.
<a href="https://agentmods.dev/skills/frank-luongt/faos-skills-marketplace/ab-test-setup"><img src="https://agentmods.dev/badge/skills/frank-luongt/faos-skills-marketplace/ab-test-setup.svg" alt="Reviewed on agentmods" width="80" height="20"></a>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.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00000 | $0.01065 |
| Opus 5.5 | $0.00000 | $0.00426 |
| Sonnet 5.5 | $0.00000 | $0.00213 |
| Haiku 4.5 | $0.00000 | $0.00106 |
Grade A, and why
ab-test-setup 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 1mo 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.
This is a copy
91% identical to ab-test-setup — 39 lines differ, which has more behind it and is treated as the original. This page carries a canonical link to it rather than competing with it.
How it starts
The opening of the file, as written. The whole thing — 237 lines — stays where its author put it; the contents beside it link to each section on GitHub.
name: ab-test-setup description: Structured guide for setting up A/B tests with mandatory gates for hypothesis, metrics, and execution readiness. Use when planning experiments, defining test hypotheses, calculating sample sizes, or validating A/B test designs. tags: [ab-testing, experimentation, cro]
A/B Test Setup
Purpose & Scope
Ensure every A/B test is valid, rigorous, and safe before a single line of code is written.
- Prevents "peeking"
- Enforces statistical power
- Blocks invalid hypotheses
Pre-Requisites
You must have:
- A clear user problem
- Access to an analytics source
- Roughly estimated traffic volume
Hypothesis Quality Checklist
A valid hypothesis includes:
- Observation or evidence
- Single, specific change
- Directional expectation
- Defined audience
- Measurable success criteria
Hypothesis Lock (Hard Gate)
Before designing variants or metrics, you MUST:
- Present the final hypothesis
- Specify:
- Target audience
- Primary metric
- Expected direction of effect
- Minimum Detectable Effect (MDE)
Ask explicitly:
"Is this the final hypothesis we are committing to for this test?"
Do NOT proceed until confirmed.
Assumptions & Validity Check (Mandatory)
Explicitly list assumptions about:
- Traffic stability
- User independence
- Metric reliability
- Randomization quality
- External factors (seasonality, campaigns, releases)
If assumptions are weak or violated:
- Warn the user
- Recommend delaying or redesigning the test
Test Type Selection
Choose the simplest valid test:
- A/B Test - single change, two variants
- A/B/n Test - multiple variants, higher traffic required
- Multivariate Test (MVT) - interaction effects, very high traffic
- Split URL Test - major structural changes
Default to A/B unless there is a clear reason otherwise.
Metrics Definition
Primary Metric (Mandatory)
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.
- 1mo ago First seen · 237 lines · 0 tokens per session scan A 858f4ff08ee4
ab-test-setup is a skill published in the GitHub repository frank-luongt/faos-skills-marketplace (37 stars, last pushed 3mo ago), licensed Apache-2.0. It costs nothing until one of its globs matches a file; then it loads 1,065 tokens. A static security scan graded it A with 0 findings. It is 91% identical to ab-test-setup, differing in 39 lines, and is treated as a copy.
Other skills, from other repositories
task-observer
Monitors task execution for skill improvement opportunities: logs patterns, user corrections and methodology worth preserving to the workspace, turns them into skill updates in a weekly review, and flags repeating work as new skills. Use during ANY multi-step task, agentic workflow, or work session. Also triggers in…
resume-tailor
Use when the user has a specific job posting and wants to customize their resume, CV, work document, and/or cover letter for that role. Also use when they say "I'm applying to..." or share a job link.
claim-check
Use when the user wants a final truth pass before submitting a resume, CV, cover letter, LinkedIn section, or application package. Also use when they ask whether a draft contains unsupported, inflated, or hallucinated claims.
resume-builder
Use when the user wants to create or update a source work document in resume or CV format, or create a source cover letter from scratch. Triggers on US resumes ("build my resume") and UK/EU-style work CVs ("build my CV", "I need a CV for a UK role", "European CV"). US academic CVs are out of scope. For first-time…
interview-coach
Use when the user has an upcoming interview, received an interview invitation, or wants to prepare for a specific role at a specific company.
cover-letter
Use when the user wants a cover letter for a specific role, company, or tightly defined target lane, especially when they ask for "just a cover letter." Do not use for generic broad cover letters.