YouTube Thumbnail Brief + 168x94 Legibility Check

How it works

Thumbnail Brief + Legibility Check turns a YouTube title and a one-line summary into a thumbnail brief, then checks it for mobile legibility before you make any image. It plans and audits; it does not draw or inspect images.

Phase 1 — Intake. Reads your title, summary and any thumbnail text you already plan. Asks 1-2 questions only if the title or summary is missing.

Phase 2 — Draft brief. Concept, one focal subject, 2-3 overlay text options (at most 4 words and 20 characters each), a 3-color palette with hex codes, a 3x3 composition map that keeps the length-badge corner clear, and a 3-element budget.

Phase 3 — Four blind reviewers. Thumb-Size Reader (text length and letter size at about 168x94 px), Contrast and Clutter Inspector (contrast ratio computed from your hex codes), Subject-Size Scout (focal subject size), Title-Promise Auditor (title redundancy and clickbait-promise mismatch). Each checks without seeing the others.

Phase 4 — Cross-check. Reviewers challenge or corroborate each other's findings.

Phase 5 — Board verdict. An issues table tagged CORROBORATED, CONFIRMED or DISPUTED, a corrected brief with re-checked numbers, a SHIP, REVISE or REWORK verdict, and one generator-neutral image prompt. Strictly SFW. No promises about views or click-through rate.

Sample output

[HAND-WRITTEN FICTIONAL SAMPLE - invented for testing.]
Title: "I Repaired a 40-Year-Old Radio in 30 Days (Here's Every Mistake)". Summary: A hobbyist restores a broken 1980s tabletop radio over one month and walks through five mistakes with the power supply and the speaker. Thumbnail text I already plan: "I FIXED A 40 YEAR OLD RADIO!!"

Real, unedited output from running this Skill on a sample problem:

"I Repaired a 40-Year-Old Radio in 30 Days (Here's Every Mistake)" — 6 issues (3 BLOCKER, 3 FIX) — verdict REVISE.

## Intake
- Title (64 characters): I Repaired a 40-Year-Old Radio in 30 Days (Here's Every Mistake)
- Summary: A hobbyist restores a broken 1980s tabletop radio over one month and walks through five mistakes with the power supply and the speaker.
- Planned text (Option A): "I FIXED A 40 YEAR OLD RADIO!!"
- (assumed) faceless workshop channel; hero object is the radio.

## Draft brief
1. Concept: a dead old radio comes back to life after a month of repairs and mistakes.
2. Focal subject: the 1980s tabletop radio, back panel open, smoke rising from the back.
3. Overlay text: A "I FIXED A 40 YEAR OLD RADIO!!" (7 words, 29 characters); B "5 MISTAKES" (2 words, 10); C "DAY 30: SOUND?" (3 words, 14), recommended.
4. Color: navy #1B2A41 background, yellow #FFD23F text on an orange #FF5A36 burst shape, no stroke.
5. Composition: radio in left and center columns, middle and bottom rows; two-line text (DAY 30 / SOUND?) top-right; soldering iron bottom-left; bottom-right corner empty.
6. Element budget: radio, text on burst, soldering iron, smoke = 4.

## Reviewer findings (blind)
### R1 — Thumb-Size Reader
- R1-1 BLOCKER — Option A is 7 words and 29 characters (limits 4 and 20); it needs 3+ lines, each under the 12% capital-height floor. Reject A.
- Checked: C is 14 characters on two lines of about 15% frame height (about 14 px at 168x94, floor about 11 px); B is 10 characters; badge zone unused.
### R2 — Contrast and Clutter Inspector
- R2-1 BLOCKER — #FFD23F on the #FF5A36 burst = 2.15:1 (script-computed), under 3:1. Put the text on plain navy: #FFD23F on #1B2A41 = 10.0:1.
- R2-2 FIX — 4 elements, budget is 3. Drop the soldering iron.
### R3 — Subject-Size Scout
- no findings. Checked: radio about 55% of frame height (floor 30%), faceless hero object, plain navy behind it, no overlap with text or badge zone.
### R4 — Title-Promise Auditor
- R4-1 BLOCKER — The smoke implies a fire or failure; the summary mentions power-supply and speaker mistakes only. Replace with a warm glow from the speaker grille.
- R4-2 FIX — Option A restates the title; B reuses the title's word "mistake".
- R4-3 FIX — C's "DAY 30" repeats the title's "30 Days". Alternative: "DOES IT PLAY?" (13 characters).
- Gap check: the title names the topic, the thumbnail adds the stake; together a complete story.

## Cross-check
- R1-1: R4 corroborates (A also restates the title); R3 corroborates (29 characters would crowd the radio).
- R2-1: R1 corroborates (the burst squeezes the letter area).
- R2-2: R3 and R1 corroborate (the iron competes with the radio silhouette and with letter room).
- R4-1: R2 corroborates (smoke on navy is extra low-contrast clutter).
- R4-2: R1 corroborates (see R1-1).
- R4-3: R1 challenges: only the number repeats, "SOUND?" adds the stake, and a day counter reads at a glance.

## Issues table
| ID | Check | Severity | Finding | Fix | Tag |
|---|---|---|---|---|---|
| R1-1 | Text length | BLOCKER | Option A is 7 words, 29 characters | Reject A; use C | CORROBORATED (R1, R4, R3) |
| R2-1 | Contrast | BLOCKER | #FFD23F on #FF5A36 = 2.15:1 | Text on plain navy, 10.0:1 | CORROBORATED (R2, R1) |
| R4-1 | Promise mismatch | BLOCKER | Smoke implies a fire the summary never mentions | Remove smoke; speaker glow | CORROBORATED (R4, R2) |
| R2-2 | Clutter | FIX | 4 elements, budget 3 | Drop the soldering iron | CORROBORATED (R2, R3, R1) |
| R4-2 | Title redundancy | FIX | A restates the title; B repeats "mistake" | Reject A; B backup only | CORROBORATED (R4, R1) |
| R4-3 | Title redundancy | FIX | "DAY 30" repeats "30 Days" | "DOES IT PLAY?" | DISPUTED — R1: only the number repeats, "SOUND?" adds the stake (your call) |

## Corrected brief
Changes: rejected Option A (R1-1, R4-2); text moved onto plain navy, burst removed (R2-1); iron removed (R2-2); smoke replaced by an orange speaker glow (R4-1). R4-3 stays as drafted.
- Focal subject: the radio, speaker grille glowing orange, back panel open but dark inside.
- Overlay text: C "DAY 30: SOUND?" (alternative if you accept R4-3: "DOES IT PLAY?"); B "5 MISTAKES" as backup.
- Color: yellow #FFD23F text directly on navy #1B2A41; orange #FF5A36 for the glow only.
- Composition: unchanged except no burst and no iron. Elements: radio, text, glow = 3.
Re-checked: C is 3 words, 14 characters; contrast 10.0:1; capital height about 15% per line; 3 elements; badge zone empty.

## Verdict
REVISE — all 3 BLOCKERs fixed and re-checked; R4-3 is yours to decide.

## Image prompt
Semi-realistic product-shot style, 16:9 horizontal frame. A vintage 1980s tabletop radio in cream plastic with a round speaker grille, seen slightly from above and in front, filling about half the frame height on the left and center of the image. The grille glows warm orange (#FF5A36); the back panel is open and its interior stays dark and simple. The background is a plain, evenly dark navy (#1B2A41). Keep the top-right area clean and empty for text added later, and keep the bottom-right corner empty. No people, no hands, no smoke, no lettering, no logos.

## Notes
- Confirm the assumptions: faceless channel, cream radio (colour was not given).
- Add the text in an image editor, bold sans-serif, about 15% of frame height per line, and view it at 168x94 px before publishing.
- Planning only: it cannot see the finished image or predict clicks; thresholds are heuristics.

Use cases

• Briefing a designer or an AI image generator with a clear, checked thumbnail plan
• Catching unreadable text and low contrast before you spend time on the image
• Spotting a thumbnail that repeats the title or promises something the video does not deliver
• Getting a clean image prompt that leaves room for text you add in an editor

FAQ

Does it generate or look at images? No. It plans from your description and checks the plan. View the finished thumbnail at 168x94 px yourself.

Will it raise my views or click-through rate? No promise either way. It checks legibility and title consistency only.

Which image tools? Any. The prompt is plain English with no tool-specific syntax.

Is it SFW only? Yes, and it refuses sexualized, gory or real-person-likeness requests.