Perhaps we can start with the earliest use in philosophy: Socrates's "daemon," which is described as an "inner voice," of judgement--benign, not malevolent. For the Greeks the term usually meant an intellgent being above men, but below the gods.
So it is from the beginning a piece of unspecified intelligence capable of some minimal judgment and of acting in the world. For Socrates, it was said to prevent him from some unwise or unjust action. For Maxwell, this judgement is again a kind of minimal prevention, the operation of his little thermodynamic trapdoor sorting out molecules into two types.
The uses by Descartes and Laplace are in some ways very different. Descartes' demon is not only malevolent, but anthropomorphic, willful, and multitalented. Laplace's demon is both supremely "intelligent" and mechanical, no mention of judgments or intentions.
So the term seems pretty informal. If the Greeks placed the daemon between men and gods, we might today place it between men and machines. It has some aspects of judgment and will, accountable neither to human will nor to mechanical causation. In which case, Laplace's demon, both godlike and mechanical, seems like the odd one out.