Structured Output Prompting: Get JSON, Not Prose

Structured output prompting means asking the model to return data in a fixed schema instead of free text. Spell out the exact keys, types, and nesting you expect, and show one filled example. A model that sees {"tags": ["a","b"], "score": 0.0} returns clean arrays and numbers far more reliably than one told to 'list some tags with scores.'

Pin down the boundaries, not just the fields. Say 'return only valid minified JSON, no markdown, no code fences,' cap array lengths, enumerate allowed enum values, and state what to emit when data is missing (null, empty string, or []). These constraints kill the stray prose, trailing commentary, and hallucinated keys that break downstream parsing.

On CinderHub you can reuse one schema across chat, image captioning, and storyboard generation, so a single prompt template feeds every model the same contract. Always validate the response and, on a parse failure, echo the error back and ask for a corrected object. That retry loop turns an occasionally-wrong model into a dependable, machine-readable data source.