My routine said it ran. It was lying.

I run an AI system that maintains itself on a schedule. One of its routines is supposed to do a job twice a week and save the result to a file. The scheduler swore it ran. Twice. lastRunAt right there - timestamped, green, smug. The file? Didn't exist. Not "saved in the wrong folder" - didn't exist anywhere. Here's the thing nobody warns you about when you wire up autonomous agents: "it ran" and "it worked" are different claims, and most of your dashboards only check the first one. The trap A scheduler firing a job tells you a process started . It tells you nothing about whether the job did the thing. My routine started, hit an early error reading a file that didn't exist yet, and just... ended. No crash. No red anywhere. It "ran." It produced nothing. For days. If I'd trusted the green checkmark, I'd still think it was fine. How I found it I stopped reading the status and went to the disk. Three checks, in order: Does the output actually exist? Not "did it run" - does the artifact it's supposed to produce exist, right now, where it claims to put it? If yes - is it fresh and non-empty? A stale or empty file is a silent failure wearing a costume. If no - read the raw run log. Not the summary. The actual transcript of what the agent did, tool call by tool call. That third check is where the truth was hiding. The summary said the routine was "episodic." The transcript said something blunter: it tried to read its own memory file, got "file does not exist," and never recovered to create it. Zero write calls the entire run. It never even tried to save anything. "Episodic" and "dies before it writes" lead to completely different fixes. The summary would've sent me down the wrong one. Steal these If you run anything autonomous: "Ran" is not "worked." Health is the artifact: it exists, it's fresh, it's not empty. Not a green dot from the thing that launched it. Described is not executed. What the spec says a routine does is a hypothesis. What's on disk is the fact. When they