Logging what an agent does is not the same as proving what it did. One is a developer tool. The other is a compliance artifact — and building it correctly changes everything downstream.
A debug log and an audit trail serve different readers. A debug log
helps you reproduce a bug. An audit trail is read by auditors, incident
responders, and legal counsel — people who need to know what the agent did,
on whose behalf, with what data, and with what result. Design it for them.
Debug logs optimize for machine readability and developer speed. Audit
trails optimize for completeness, tamper-evidence, and human
accountability. They are not the same artifact shaped differently. They
are different artifacts with different retention rules, storage
requirements, and access controls.