Keep the core idea clear.
Before adapting a video for multiple channels, decide what it says in a single sentence. Your agent can use that sentence as the anchor for every caption. The words can change while the message stays recognisable.
Write for the context.
A person finding your video on YouTube may need a descriptive title. Someone scrolling Instagram may respond to a short opening line. Give your agent the context for each channel instead of asking it to copy one caption everywhere.
Review the whole post.
Captions are only one part of the result. Check that the media fits the destination, the title makes sense and the timing matches your plan. Platform requirements can change, so confirm the current requirements for the content you want to publish.
Keep the scheduling request specific.
Try: “Use this video on Instagram, Facebook, TikTok and YouTube on Friday at 9am in Sydney. Write a separate caption for each and show me the drafts first.” A precise request makes the intended result much easier to review.