Free Video Ad Hook Check — First 3 Seconds

The first seconds of a short video ad are where scripts most often go wrong, and the faults are plain ones: an opening line that takes eight seconds to say, an opening that never names the product, two calls to action. Free Video Ad Hook Check reads the script as text and measures exactly those points, the same way every time, before anyone records it.

Give it a script as a plain text file, JSON or a CSV with one script per row, plus (if you know them) the words that name your product and your audience. It prints a pass/fail table:

| Check | Result | Detail |
|---|---|---|
| hook-fit | PASS | first line ~2.0 s of a 3.0 s window (5 words) |
| hook-terms | PASS | product: sourdough; audience: busy, mornings |
| cta | PASS | line 5 starts at ~11.2 s of ~12.8 s (88%) |
| **Overall** | **PASS** | |

What it does:

• hook-fit: can the first line be spoken inside the opening window (3 seconds by default)?
• hook-terms: do your product and audience words appear in what is spoken inside that window?
• cta: exactly one call-to-action line, starting in the closing part of the script
• Three input formats (text, JSON, CSV), one script or many, with a summary table for many
• English and Japanese scripts (Latin words and CJK characters are timed separately); a Japanese example is included
• --json, --strict and an exit code (0 / 1 / 2) for scripts and agent loops
• Your own limits in a small JSON settings file; unknown keys are rejected so a typo cannot silently fall back to a default
• SKILL.md tells an AI agent when to run it, and lists the questions the tool cannot answer (one promise, three rewrites of the opening) so the agent answers them itself and re-checks every rewrite with the tool

Honest limits, stated in the README: timings are estimates from reading speeds, not audio measurements; it does not check or claim to meet any ad platform's rules; it promises no results; the default phrase list is a short general example you should edit; it reads text only and never connects to an ad account, a model or the network.

Keep going

This is the small free version with three checks. The full tool, "Video Ad Hook Checker — First 3 Seconds and CTA", adds four more checks (claims that need evidence, subtitle width, spoken length against a target, script structure), a side-by-side comparison of a rewrite with the original, and an estimated timeline of every line. Nothing in this free version depends on it.

What is inside

• SKILL.md, README.md, LICENSE
• scripts/hook_check.py
• tests/test_hook_check.py (63 tests)
• examples/: a passing script, a failing script, a Japanese script, a CSV of two scripts, a settings file and the real output of each
• images/, listing/

Requirements and safety

Python 3.9+ and nothing else. The tool makes no network calls, needs no credentials and writes no files. It only reads the file you point it to.

License

Personal, non-transferable license for your own projects, including commercial work. No resale or redistribution.