After an incident involving a transit agent's automated rider notifications, the compliance office needs a full trail of every tool call the agent made in the hours before the incident. Where should they reconstruct this from?

Agent Gateway's audit logging captures individual tool calls as the agent makes them, and pairing that with Cloud Logging gives the compliance office a queryable, timestamped record of the agent's actions across the incident window, which is exactly the full trail the office needs to reconstruct. Agent Registry's version metadata tells them which agent build was active, which is useful context for the investigation but is not itself a record of individual tool calls; knowing the version doesn't reveal what that version actually did during those hours. Sensitive Data Protection's scan history covers a completely different concern, sensitive-content patterns found in stored data, and has no relationship to tracking tool-call activity during an incident window. The rider notification content shows the final output the agent produced, but it only reflects what was communicated externally, not the underlying tool calls, retrievals, or decision steps that led there, so it would leave significant gaps in a tool-call trail. A scope caveat: reconstructing the trail depends on the logging window having actually retained data for the incident period, so retention settings matter here too. As an operational check, the compliance office can query Cloud Logging for the agent's identity across the incident window and confirm every tool call in that period has a corresponding Agent Gateway log entry.