Lesson 3 · 10 min
Constraints: the secret weapon
Telling the model what NOT to do is often more powerful than telling it what to do.
Negative space
LLMs are people-pleasers. Without constraints, they hedge, pad, and add caveats. Constraints carve away the bad outputs — like a sculptor.
Four kinds of constraints worth knowing:
- Format — JSON schema, Markdown, plain text, no Markdown
- Length — exact word count, max bullets, max sentences
- Style — tone, register, vocabulary
- Negative — explicit don'ts (no apologies, no marketing language, no caveats)