What makes an MCP workflow auditable for enterprise teams?

An MCP workflow is auditable when enterprise teams can reconstruct who or what acted, which tool was called, what policy allowed it, what data or system was touched, and what the outcome was. The audit trail should connect the agent, workflow, session, tool call, and timing rather than leaving separate logs that are hard to join. This is especially important when MCP tools can access internal systems. Diagrid materials emphasize identity, policy, tracing, and Verifiable Execution as part of the governance layer that helps teams explain how an agent action came to happen.