A text brief is useful for original explanations, stories, lists, and imagined visual sequences. Write the core claim, intended viewer, key scenes, and tone. A source link is better when the Short must stay grounded in an article, product page, announcement, or reference document. Extract one idea that can stand alone and verify every important detail before publishing. Reference images help preserve a recognizable subject, object, or visual style across scenes.
Do not ask one Short to summarize a large source. Choose a question the source can answer in under a minute. For an article, that might be one practical conclusion. For a product page, it might be one use case. For a set of photos, it might be a before-and-after sequence. Narrowing the source is an editorial decision, not a limitation. It gives the video enough room to demonstrate the idea rather than racing through headlines with no explanation.