MCP Prompts vs System Prompts
A system prompt is part of the host's model instructions. An MCP prompt is a server-published reusable template that a compatible client can discover and request.
| Area | System prompt | MCP prompt |
|---|---|---|
| Owned by | Host/application | MCP server |
| Purpose | Global behavior and policy | Reusable domain workflow/template |
| Discovery | Usually app code/config | Protocol discovery |
Do not delegate core safety policy
Host-level security, authorization expectations, and non-negotiable behavioral constraints should remain under host control. A third-party server-provided prompt should be treated as untrusted content unless you explicitly trust and review it.
Security note: server-provided prompts can influence model behavior. Do not automatically treat them as higher-trust instructions than your application policy.