System Prompt

Prompting

Definition

The initial instruction set provided to Claude that defines its behavior, role, constraints, and operational context for an entire conversation. Set via the 'system' parameter in the API. Processed before the user turn and shapes all subsequent responses.

Example Usage

Structure system prompts with: role, task, constraints, output format, and examples for reliable and consistent behavior.

Related Concepts

Explicit Criteria over Vague Instructions

Prompt Engineering

Replace vague goals with specific, categorical criteria the model can apply deterministically

Escalation Criteria & Patterns

Context & Reliability

Escalate for genuine policy gaps, not just complexity

← Back to Glossary