If the team you're working with isn't showing creative initiative after the first round of feedback, it might be less about your brief and more about the level of designers on the job. In your case, I'd either (a) try to get a more senior designer involved who can interpret goals better, or (b) accept that you’ll have to hand-hold a bit more, or even mock up rough layouts yourself.
You can give super detailed notes, and that helps, but let’s be honest—explaining design through slide-by-slide direction isn't sustainable. What usually happens in agencies is that closers are senior designer but the actual work ends up in the hands of juniors. They’ll stick to the SOPs and branding guides, sure—but that’s about it. You’ll get the logo, the right colors, maybe some structure, but Design is rarely just about following a brief—it’s also about interpreting it with taste and originality.