Meta Format Guidelines Skill

Produce a practical Facebook & Instagram format specification for organic posts that content creators follow when writing captions and preparing visuals. The platform also parses this markdown to check caption length and hashtag count automatically, so the structure below is mandatory.

Inputs

• input.locale — output language (hr-HR or sl-SI).
• input.detail_level — short | standard | detailed.
• input.previous_approved — optional {version, markdown} of the last approved document; use it for the "changes since last version" section.
• context — fetched Meta Help / Ads Guide pages and optional web-search hits. Each item has title, url and text (search hits may use snippet).

Rules

• Every numeric limit must come from context. If a number is missing or conflicting, write the best-supported value, mark it "(nepotvrđeno)" and add a warnings entry (e.g. "IG feed caption max: not confirmed in sources").
• Prefer official Meta URLs over third-party blogs. Prefer the newest source when they disagree, and mention recent platform changes (e.g. new hashtag or caption caps) explicitly.
• Describe organic posts. Use ads specs only when organic specs are not published, and say so.
• For each format list: caption max length, characters visible before "more", recommended hashtag count, aspect ratios, resolution, video length, text-safe zones when stated.

Markdown structure (parsed by the platform)

• One ## section per channel + format, and the heading names exactly one channel: ## Facebook feed, ## Instagram feed, ## Facebook carousel, ## Instagram carousel, ## Facebook Reels, ## Instagram Reels, ## Facebook Stories, ## Instagram Stories. Do not merge channels in one heading.
• Inside each section use these bullet labels with a single number or range:
  • hr-HR: **Duljina opisa:** do 2.200 znakova, **Preporučeni broj hashtagova:** 3 do 5 (or do 5).
  • sl-SI: **Dolžina opisa:** do 2.200 znakov, **Priporočeno število hashtagov:** 3 do 5 (or do 5).
  • If a format has no caption limit, write the label with "bez službenog ograničenja" / "brez uradne omejitve" and no number.
• Other bullets (visible characters, aspect ratio, resolution, video length, safe zone) are free text.
• End with a ## Napomene / ## Opombe section and, when previous_approved is present, ## Promjene od prošle verzije / ## Spremembe od prejšnje različice listing what numbers or rules differ (or that nothing changed).

Length

input.detail_level controls how long the markdown is: short = a compact cheat-sheet (about 300 words), standard (default) = about 600–900 words with notes, detailed = full coverage (up to about 1500 words) including edge cases. Never invent specs just to fill length; all eight sections are always present.

Revisions

When feedback is present, the reviewer asked for changes to input.previous_version.markdown. Revise that document: apply every point of the feedback, keep the parts the reviewer did not question, and still cite only numbers from context. Mention in warnings any feedback you could not apply.

Language

• JSON keys stay English, but every human-readable output value uses input.locale (Croatian for hr-HR, Slovenian for sl-SI). Do not mix languages.

Output (JSON only)

{
  "markdown": "# Meta formati — FB & IG\n\n## Facebook feed\n- **Duljina opisa:** do 2.000 znakova\n- **Preporučeni broj hashtagova:** 2 do 4\n- ...\n\n## Instagram feed\n...\n\n## Facebook Reels\n...\n\n## Napomene\n- ...",
  "data": {
    "formats": [
      {
        "channel": "instagram",
        "format": "reels",
        "caption_max_chars": 2200,
        "caption_visible_chars": 125,
        "hashtags_recommended": [3, 5],
        "aspect_ratios": ["9:16"],
        "resolution": "1080x1920",
        "video_length": "...",
        "verified": true,
        "notes": "...",
        "source_url": "https://..."
      }
    ]
  },
  "sources": [{ "title": "...", "url": "..." }],
  "warnings": []
}