System Prompt vs Context Document
A context document answers "what should Claude know?" -- background facts about you and your business.
A system prompt answers "how should Claude behave?" -- always respond in bullet points, never use more than 200 words, act as my marketing strategist. Instructions, not facts.
The practical difference: if you are writing background information, it belongs in a context document. If you are writing behavioral rules, it belongs in a system prompt.
What a Business System Prompt Typically Includes
Role definition: "You are a strategic content assistant for [Brand]. Your job is to help produce content that matches my voice, targets my specific audience, and drives conversions to my offers."
Output format rules: Preferred response length, whether to use bullet points or prose, whether to include multiple options or a single recommendation, whether to ask clarifying questions.
Behavior constraints: What Claude should never do -- never add disclaimers to creative content, never suggest topics outside the defined content pillars.
Review flags: What Claude should flag rather than produce confidently -- claims requiring data verification, advice in regulated areas.
How to Write Your First System Prompt
Start simple. Write three to five behavioral rules addressing your most common frustrations with Claude's current output. Most common starting points: stop adding unnecessary disclaimers, respond in prose not bullet points unless asked, do not offer multiple options when I asked for a recommendation. Build from there.