prompt-engineering

A prompt states a goal and gets out of the way. Everything else in it is load — spent on every run, taken from the attention the model would otherwise put on the work — so each line has to buy more than it costs. What follows decides three things: whether a line exists, where it sits, and how it is worded.

Where a line came from

Ask this before asking whether the line helps. A line can be true, relevant, and still worth cutting, so usefulness does not settle it. Provenance does, and you can answer it from memory:

• The user ruled it — a decision, preference, or constraint they stated. Nothing derives it. Keep.
• The world holds it, out of the run's reach — an unwritten convention, a failure you observed, a fact outside what the run will read. Keep, and prefer a pointer to the source over a copy that can go stale.
• It counteracts a default you have watched the model take — keep, when the default is observed rather than feared.
• You worked it out from material the run will also read — cut. A conclusion available in the corpus is one the run reaches itself, so writing it down buys nothing and spends load on every invocation.

That last class is the one that feels most earned, because you did the work to reach it, and it is where over-specification comes from. Two tells: a line you could justify from the same sources the run gets, and a sentence that merely argues for the instruction above it without adding information admitted by the tests above.

A choice the request left open belongs to whoever made the request. Some of what you would add is not padding but a decision — what ranks one candidate over another, an exception to a rule they gave you, a deliverable beyond what they asked for. It reads as thoroughness and it commits them to something they never chose, under their name, in a file they will quote back later. Ask where the answer would change the work; leave it out where it would not.

A finished prompt looks thinner than you expect it to, and that is the result rather than a warning sign. Two rulings and a goal make a short document; the pull at that point is to fill it out — a section on how to rank, a definition of the term in its own name, a third source of evidence nobody asked for — and everything reached for that way comes from the class above. When it reads as too slight, check the goal is stated and the rulings are in it, then ship it.

The older question — would the model do this without the line? — asks for a prediction about the model's own counterfactual behaviour, which is not reliably answerable from the inside. Ask it second, of what provenance already admitted: it can still cut a line provenance allowed, never keep one provenance rejected.