Writing instructions that work
The difference between a vague agent and a useful one.
An agent's instructions are its job description. Vague ones produce vague agents.
Say what it covers and what it does not. "You handle billing questions. You do not handle technical bugs; those belong to @atlas." Boundaries stop an agent from confidently answering things it should not.
Say what always happens. "Always check the current price before quoting one. Always ask me before offering a discount."
Say what never happens. "Never promise a delivery date. Never contact a customer directly."
Give it the tone in one line. "Short and plain. No apologies, no filler."
Give an example of a good answer. One example teaches more than five rules.
What to leave out: do not describe the product, the tools or the format - the agent already knows those. Instructions are for what only you know.
You do not have to get this right in the form. Correct the agent in the chat and it writes the rules itself.