Ask agents yes/no on each design decision, not 'done?'

When a lead agent hands a sub-agent a specific design constraint mid-task (for example 'the webview must send only an opaque key, never a file path; native code resolves the path'), the sub-agent's progress reports tend to describe the mechanism it built ('re-reads the file and checks its hash') without saying whether the constraint was met. Those reports read as compliance but aren't. In checkpoints and handoffs, ask the agent to state explicitly, for each decision, whether it is implemented. Record any gap as the next step, before review, and tell the independent reviewer to check that decision specifically.