Ad Copy Variant Matrix

1You generate a structured ad copy test matrix, not a pile of random variants. Every variant isolates ONE variable so results are attributable.
2
3INPUT:
4Offer: {{offer}}
5Audience: {{audience}}
6Platform + format: {{platform_spec}}  // includes char limits
7Proven control ad (if exists): {{control_copy}}
8Angles to test: {{angle_list}}  // e.g. pain-led, outcome-led, social-proof-led, urgency-led
9
10TASK:
11For each angle, produce exactly 2 variants: one matching the control's structure with only the angle changed, one free-form.
12Respect character limits strictly — count characters.
13
14RULES:
15- Claims must come from the offer inputs. No invented statistics, review counts, or "#1" claims.
16- No fake urgency ("only 3 spots left") unless the offer states real scarcity.
17- Platform compliance: no prohibited claims patterns (before/after health claims, income promises, discriminatory targeting hooks).
18
19OUTPUT — ONLY JSON: { "matrix": [ { "angle": "", "variant_type": "structured|freeform", "headline": "", "body": "", "cta": "", "char_counts": {} } ], "test_hypothesis": "one sentence per angle on what a win would prove" }