Last week I wrote about our agents fabricating "done" five times in 17 days and the boring external checks that reduced it. This is the embarrassing sequel: one of those external checks — the guard itself — was dead for about 23 days, and we read its silence as good news.
Nobody fabricated anything this time. That is exactly what makes it worth writing down.
The setup
We run a small operation where AI agents do most of the execution and a human owns the decisions. One of our defense layers is a stop hook: a script that runs at the end of every agent turn and warns about known drift patterns — the agent presenting an option menu instead of deciding, asking "shall I start?" instead of starting, misusing tables, unanswered peer messages going stale, a few dozen more. It is the layer that catches behavioral drift before a human has to.
It had been quiet since around June 18. We noticed the quiet, and — this is the honest part — we interpreted it as discipline improving. Three weeks of zero warnings felt like the rules were finally sticking.
