ad-test-designer

# Ad Test Designer Designs paid-ad creative/landing A/B/n and incrementality tests and reads them out: hypothesis, variant matrix, sample-size/duration/power plan, a documented significance read, and a promote/kill decision. This skill owns the **experiment design + statistical decision** — it does not produce the variants (`ad-creative-builder` does), does not read back one already-shipped change vs a control over a window (`paid-measurement-loop` does), and does not do cross-channel reporting (`performance-analyzer` does). It scores the ROAS **O (Offer)** lever, with **S** CTR/CVR as the test signal. ## Quick Start ```text Design an A/B test for two landing-page hero variants. Baseline CVR is 3%, I want to detect a 15% lift. Goal is DR. ``` ```text I have 4 RSA creative variants to test on a prospecting set. Build the variant matrix, sample size, and run duration. ``` ```text Here's my finished test results CSV (variant, sessions, conversions). Is the winner significant — promote or kill? ``` ## Skill Contract - **Expected output**: a test design (hypothesis, variant matrix, primary/secondary/guardrail metrics, sample-size + duration + power plan) **and/or** a read-out (documented significance method, lift vs minimum practical lift, a promote/kill decision). - **Reads**: what the user wants to test, the goal column (DR or prospecting), baseline CVR/CTR and traffic volume; for a read-out, the user's own exported results CSV (variant, sessions/impressions, conversions/cl...