The outcome is that the agent performs the "best" action (according to the utility function) - and then the rest of the world responds to it according to physical law. The agent can only control its actions. Outcomes are determined from them by physics and the rest of the world.

This is backwards. Agents control their perceptions, not their actions. They vary their actions in such a manner as to produce the perceptions they desire. There is a causal path from action to perception outside the agent, and another from perception (and desired perception) to action inside the agent.

It is only by mistakenly looking at those paths separately and ignoring their connection that one can maintain the stimulus-response model of an organism (whether of the behaviourist or cognitive type), whereby perceptions control actions. But the two are bound together in a loop, whose properties are completely different: actions control perceptions. The loop as a whole operates in such a way that the perception takes on whatever value the agent intends it to. The action varies all over the place, while the perception hardly changes. The agent controls its perceptions by means of its actions; the environment does not control the agent's actions by means of the perceptions it supplies.