AI for Ad Copy: Variants With Guardrails

The angle is the part that decides whether an ad works, and it should come from your positioning and a read of what competitors are already saying. The write ads from competitor research guide covers how to find an open angle. This guide starts once you have one.

Google responsive search ads accept a minimum of 3 and a maximum of 15 headlines, each up to 30 characters, and 2 to 4 descriptions of up to 90 characters, and Google assembles combinations from them [s1]. That has a direct consequence for AI prompts: every headline must make sense next to any other, so variants should not depend on being read in order or repeat each other.

Pinning a headline to a position guarantees it shows, but Google notes that pinning reduces the number of combinations that can be matched and is not recommended for most advertisers [s1]. Keep pins for the one line that must always appear, such as a required disclaimer.

Meta publishes recommended text lengths per placement and format in its Ads Guide, and the recommendations are short [s2]. Build the current recommendation for your placement into the prompt, and put the key message in the first line, since longer text can be cut off.

Write 15 headlines for a Google responsive search ad using only the brief below. Each headline must be 30 characters or fewer including spaces, make sense on its own, and make sense next to any other headline. Write them in groups: 4 that state the angle, 3 that name the audience, 3 that state a proof point from the allowed claims, 3 that state the offer, 2 that include the keyword [KEYWORD]. Do not repeat the same idea in two headlines. Use only the allowed claims. Do not use any banned claim. Output a numbered list, one headline per line.

BRIEF:
[PASTE BRIEF]

Write 4 descriptions for the same responsive search ad, each 90 characters or fewer including spaces. Description 1 expands the angle, description 2 gives a proof point, description 3 answers the objection "[MAIN OBJECTION]", description 4 states the offer with a clear next step. Each must stand alone. Use only the allowed claims and none of the banned ones.

BRIEF:
[PASTE BRIEF]

Write 5 versions of primary text for a Meta ad using the brief below. All five express the same angle, but each opens differently: a question, a specific situation the audience recognizes, a short customer-style observation (not a quote, not attributed to anyone), a direct statement of the benefit, and the offer first. Put the core message in the first sentence. Keep each version within [RECOMMENDED LENGTH FROM META ADS GUIDE]. Write in this voice: [PASTE 3 RULES FROM YOUR BRAND VOICE]. Use only the allowed claims.

BRIEF:
[PASTE BRIEF]

Here are the three objections our audience raises most often, with the answer we give to each and the evidence for it. For each objection, write one headline under 30 characters and one description under 90 characters that answer it without restating the objection negatively. Use only the answers and evidence provided. OBJECTIONS, ANSWERS AND EVIDENCE: [PASTE]

BRIEF:
[PASTE BRIEF]

Grouping headlines by category in the first prompt is what makes the set work. A model asked for "15 headlines" tends to produce fifteen phrasings of one line; asked for categories, it produces a set Google can actually combine into different ads.

The legal responsibility for an ad sits with the advertiser, not with the tool that drafted it. In the US, the FTC's guidance for small businesses says advertising must be truthful and not misleading, and that advertisers must have evidence to back up their claims before the ad runs [s3]. Comparative claims are allowed when truthful, and need the same support [s3].

Below are ad variants and the brief they were written from. For every variant, list each factual claim it makes. For each claim, say whether it appears in the allowed claims, and quote the allowed claim it matches. Mark any claim that is not in the allowed list, any number, any superlative such as best or fastest, any competitor name, and any wording that could read as a customer quote. Do not rewrite the ads.

ADS:
[PASTE VARIANTS]

BRIEF:
[PASTE BRIEF]

The temptation with AI is to launch everything it produces. On a small budget that spreads spend so thin that no variant collects enough results to be judged. A better habit is to generate twenty, cut to the five that best express the angle, and test those against one another or against your current best ad.

Change one thing at a time between variants: the opening, the proof point or the offer. If two variants differ in everything, a winner tells you nothing about why it won. The creative testing for small budgets guide covers how to size a test.