Say What to Do, Not Just What to Avoid

A prompting habit of phrasing instructions as what you want Claude to do, not only what to avoid — 'write in plain, warm English' rather than 'don't be so formal and don't use jargon'.

A prohibition removes one option but leaves every other direction open, so Claude still has to guess where you actually want to go. A positive instruction names the destination directly. 'Don't be formal' could land anywhere from casual to sloppy; 'write like a friendly colleague explaining over coffee' points at one clear target. Concrete, positive directions are simply easier to follow than a list of things not to do.

Whenever you catch yourself writing 'don't', 'avoid', or 'stop' — pause and ask what the positive version is. Especially useful for tone, style, and scope instructions.

Genuine hard constraints and safety rails, where a firm prohibition is exactly right ('never include real customer names', 'don't call any external API'). Those should stay as explicit don'ts.

Rewrite your approach around what I want, stated positively: <describe the target — the tone, structure, or content you're aiming at>. Where I have a real constraint, I'll flag it as a hard rule. Otherwise, aim at the target rather than listing what to avoid.

Instead of 'don't make it long and don't use bullet points and don't be dry', you write 'give me two tight paragraphs with a conversational voice and one concrete example'. Claude has a clear target and hits it, rather than dodging three prohibitions into somewhere you didn't intend.

Pair a positive instruction with a short example of the target ('like this: …'). The example resolves any remaining ambiguity in the positive phrasing and is far more precise than any amount of do-and-don't description.

• Converting a real safety constraint into a soft positive suggestion, weakening a rule that should be firm.
• Piling up positive instructions until they contradict each other — pick the few that matter.
• Assuming 'don't do X' tells Claude to do the opposite of X; it only rules out X, nothing more.