Budgets Are the Only Guardrail Agents Respect

Ask an agent nicely to stay within budget and it will, until the one task where staying within budget requires giving up. Enforce the budget in the runtime and the agent has no choice at all.

Advisory versus enforced

A prompt instruction is advisory. A policy engine that refuses the tool call once a fleet, task, or hourly ceiling is hit is enforced. We ship the second kind exclusively.

What breaks without it

Every incident we have been called in to fix involved a system that trusted the model to self-regulate cost or scope. The fix is never a better prompt — it is a budget the model cannot argue its way past.