Codex and coding agents need stronger scope control, not only better code generation

I agree with the framing. The missing control surface is often not “better generation”, but a small contract the agent can be checked against while it works. The pieces I would want to see first-class are: * a scope ledger: files/directories the agent is allowed to touch for this task; * an explicit non-goal list: things that may look related but must not be changed; * a diff budget: maximum number of files or behavioral surfaces before the agent must stop and ask; * a stop condition: what evidence counts as done; * negative checks: tests or inspections proving it did not refactor adjacent code, change public API, or alter config unexpectedly. The important part is that these should be machine-checkable, not only written as prose in the prompt. Otherwise the model can “agree” with the boundary and still drift once it starts solving.