A pull request changes three lines in a prompt. The source diff is tiny. The resulting agent run adds a tool call, skips a planning step, changes its recovery path, and takes twice as long.
Which diff describes the risk more accurately?
Both do—but they describe different things.
I maintain AgentInspect, an open-source TypeScript toolkit for inspecting agent runs locally. I designed its run-diff workflow around a simple idea: code review tells us what the developer changed; execution evidence tells us what the agent did differently. The examples below use synthetic fixtures verified against agent-inspect@6.17.4.
Source changes and behavior are no longer tightly coupled
