A spending limit written in a prompt is not a control. It is a piece of text, sitting in the same context window as everything else the model reads, competing for the model's attention with the task, the tool output, and whatever a third party managed to get in front of it. When that limit and an instruction to spend disagree, nothing technical decides between them. The model decides. That is the whole problem. We build Veyline at Payload, so our position is stated plainly up front. Enforceme...