It's not quite that easy. For the simplest example, look at https://enclose.horse/play/dlctud, where the naive solution will waste two walls to fence in the large area. Obviously, you can construct puzzles that have lots of these "bait" areas.
Like the other comment suggested, running a loop where you keep adding constraints that eliminate invalid solutions will probably work for any puzzle that a human would want to solve.
Like the other comment suggested, running a loop where you keep adding constraints that eliminate invalid solutions will probably work for any puzzle that a human would want to solve.