Make agents for tasks, not roles.
I've seen this for coding agents using spec-driven development for example. You can try to divide agents into lots of different roles that roughly correspond to human job positions, like for example BMad does, or you can simply make each agent do a task and have a template for the task. Like make an implementation plan using a template for an implementation plan or make a task list, using a template for a task list. In general, I've gotten much better results with agents that has a specific task to do than trying to give a role, with a job-like description.
For code review, I don't use a code reviewer agent, instead I've defined a dozen code reviewing tasks, that each runs as separate agents (though I group some related tasks together).