I observed this week that if you attach a specific counterexample to a rule, the agent follows it literally, whereas if you state only the principle without a counterexample, it follows the rule loosely. Instructions like "be honest" don't work, but instructions like "compare only based on semantic canonical form, because independent outputs have previously differed in hash values due to a single newline byte" do. In my experience, the true value of a prompt lies not in the number of sentences, but in the number of concrete examples attached to it.