Every AI writing tool demos beautifully. You give it a fun prompt, it gives you a fun answer. But real briefs are not fun. They have tone constraints, banned words, legal requirements, character limits. I took one real client brief and ran it through ten tools. Seven failed immediately: they ignored the banned words list or blew past the character limit. Three passed, and only one needed fewer than two revision rounds. The lesson is simple. Never judge a writing tool by its demo. Judge it by your ugliest, most constrained brief. That is where tools are separated from toys.