“Write captions” leaves the model to guess the length, the platform and the shape. Say exactly what you want back — a table with these columns, captions under this many characters — and the output drops straight into your deck or scheduler.
Write captions for our new cookie on social media.
Write captions for our new cookie as a table with three columns — Instagram (max 125 characters), TikTok (max 80), LinkedIn (max 200). Three rows. No hashtags in the text; list them in a fourth column.
The prompt
Copy-ready prompt
Return the result as [FORMAT — e.g. a table / a numbered list / plain paragraphs]. [If a table:] Columns: [COLUMN 1], [COLUMN 2], [COLUMN 3]. Rows: [NUMBER]. Length limits: [e.g. max 125 characters per Instagram caption]. Leave out: [e.g. hashtags inside the text, emojis, the brand name]. Task: [THE TASK].
Why it works
Anthropic’s guide asks you to “be specific about the desired output format and constraints.” Google’s Gemini guide says the same in three parts: define the response format (tables, lists, JSON), specify length requirements, and clarify what not to include.
Use it for
Anything that goes straight into another tool: a comparison table of concepts for a deck, captions per platform, a shot list with durations. The character limits are yours to check against each platform’s current rules.
Sources
- Anthropic — Claude prompting best practices — platform.claude.com (accessed 29 Sep 2026)
- Google — Prompt design strategies for the Gemini API (updated 17 Sep 2026) — ai.google.dev (accessed 29 Sep 2026)
More tricks and templates in the Prompt Lab. Want this applied to your brand’s brief? Start a project.