The Causal Knowledge Handoff
Tasks are linear; reasoning compounds. The diagnostic: would this person know what to do if the brief changed by 20%? Hand off the model, not just the actions.
The cheap form of delegation is to hand someone a task. The expensive — and durable — form is to hand them the reasoning that lets them decide what the task should be. Tasks are linear; reasoning compounds.
The diagnostic is to ask, after handing off: would this person know what to do if the brief changed by 20%? If yes, you handed off reasoning. If no, you handed off a task and you'll be handing off the next one too.
This is why playbooks beat checklists for anything that varies, why a written rationale beats a written instruction, and why the highest-leverage thing a senior person does is to articulate the model they're operating from — not just the actions they're taking.