Glossary

System prompt

The system prompt is the standing instruction — the rules an assistant carries into every conversation.

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Why it matters

It is where boundaries are set. An assistant with no explicit instruction about what to decline will attempt whatever is asked, so the categories you name here largely determine its worst behaviour.

  • Assistants attempting questions well outside their remit
  • Tone that does not match the surrounding brand
  • Boundaries assumed rather than stated

What belongs in it

Role, tone, what to do when it cannot answer, and the categories it must decline outright. Be specific: 'do not estimate delivery dates' is enforceable in a way that 'be careful about shipping' is not.

It is not where knowledge goes

A common mistake is pasting documentation into the system prompt. That consumes context on every request, does not scale past a few pages, and cannot cite. Knowledge belongs in retrieval; the prompt is for behaviour.

Common questions

Can I put my FAQ in the system prompt?
You can, and it will work badly past a handful of entries — it burns context on every request and produces no citations. Index it as content instead.
How specific should the rules be?
Specific enough to be testable. Write the rule, then ask the assistant the thing it should refuse and check that it does.

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