Short answer
You turn a market idea into a machine-readable strategy spec by turning the idea into a repeatable decision rule, attaching realistic turnover and risk constraints, and checking whether the workflow still holds up once the flattering assumptions are removed.
In aI trading prompts and strategy specs, the useful version of this workflow is the one that survives a clear benchmark, realistic execution assumptions, and a portfolio context that does not quietly change the rules after the backtest is done.