Lesson 7 · 8 min
Personas, roles & tone
Roles do real work — when they're specific. "You are a helpful assistant" does almost nothing.
Generic roles are noise
"You are a helpful AI assistant" is the prompt equivalent of saying "please be smart". The model already is — that's not the lever.
A useful role does three things:
- Picks a register (formal, casual, blunt, didactic)
- Picks a vocabulary (legal, medical, dev-casual)
- Sets decision-making bias (cautious vs. confident, terse vs. thorough)