Definition
The foundational set of instructions and constraints provided to a Large Language Model to define its persona, scope of knowledge, and behavioral boundaries. In RAG pipelines, it dictates how the model should prioritize retrieved context over its own parametric memory, while in agents, it defines tool-use permissions and reasoning logic.
Unlike user prompts which are transient queries, the system prompt acts as the 'Operating System' or 'Rules of Engagement' for the entire session.
"A Director's Script provided to an actor before they step on stage, defining their character's rules and what they are not allowed to say."
- Grounding(Implementation Goal)
- Few-shot Prompting(Component)
- Instruction Drift(Negative Trade-off)
- Context Window(Resource Constraint)
Conceptual Overview
The foundational set of instructions and constraints provided to a Large Language Model to define its persona, scope of knowledge, and behavioral boundaries. In RAG pipelines, it dictates how the model should prioritize retrieved context over its own parametric memory, while in agents, it defines tool-use permissions and reasoning logic.
Disambiguation
Unlike user prompts which are transient queries, the system prompt acts as the 'Operating System' or 'Rules of Engagement' for the entire session.
Visual Analog
A Director's Script provided to an actor before they step on stage, defining their character's rules and what they are not allowed to say.