Agents Are Where Microservices Were in 2015 — Roberto Milev & Uday Kanagala, Navan

A travel agent that buys a ticket days after receiving an instruction raises a specific authorization problem: whose permission applies when the purchase actually happens? Travel-and-expense company Navan uses this example in its conference talk to explain why its checks surround individual tool calls. The system examines actions before and after execution, where the consequences become concrete.

The same reasoning changes testing. Navan describes evaluating the sequence of steps an agent takes, rather than judging only its final answer. A plausible confirmation message is insufficient evidence that the agent followed an acceptable process to reach it.