You can see from this that the formulation of the problem presupposes a distinction between direct consequences of actions (ones that attach directly to an action, and that are ensured by the successful performance of the action) and other consequences. This assumption is generally accepted without question in the AI literature on action formalisms. You can make a good case for its common sense plausibility—for instance, many of our words for actions (‘to warm’, to ‘lengthen’, ‘to ensure’) are d