I believe the ultimate goal for any software product is to lower the barrier to entry. It used to take months of study just to get started with coding, and at least half a year to a year to build a functional website. Now, you can practically "talk" things into existence—even if it takes a few rounds of prompting. Because of this, I don't think there will be a "standard" way to develop in the future. Code is ultimately a tool to solve human needs at the lowest possible cost, so naturally, the cost of writing that code should be as low as it can get.

IMO, there is no such normative specs. Just tell your agent what you want and teach it until it gives exactly what you want.