An agent edits the wrong config file, then spends forty minutes trying to repair its own repair. The user files a bug with a screenshot of the last message. The maintainer asks for logs, and the logs live in four places: the provider’s usage page, the tool server’s stdout, the framework’s debug output, and a terminal scrollback that closed with the window. Nobody can say what the agent saw on turn six.

A gigabyte of disk costs almost nothing. The same gigabyte sent to a log vendor that prices by ingestion costs real money, and pasted into a model’s context window it costs money and answer quality at the same time. Storage is cheap per byte. Everything that touches the bytes afterward is not: ingestion fees, query time, bandwidth on a thin link, a context window that holds only so much, and the attention of whoever has to read the result. Observability is the oldest place this shows up, and agents have just made it louder.