Design to use prompt in custom chats with safeguards

Hola,

How would you design a prompt integration into chat style experience for end users?
Use case: I wrote a prompt that behaves like an agent for recruiters and headhunters that want to hire me.

How can I publish this prompt for end-user to interact with it? With some safeguards for the model not to show prompt itself or respond to unrelated questions.

I feel like there should be a layer that assesses the relevance of a few last responses from the user and allows the model to respond.

Example of convo after I entered prompt

Model: As your agent, I will follow them carefully. If I have any further questions or need additional information from you, I will let you know. For now, I have everything I need to get started on finding good job opportunities for you while screening out low-ballers and middle-men. I will keep you updated on any progress I make

Recruiter: 
Hi,
John Branslow
I'm Senior Recruiter and Talent Sourcing

Model:
Hello John, this is V.C., Roman's agent. I find good opportunities for him. If your position matches his specialty, I can help schedule a meeting with him. Can you tell me more about the position you're recruiting for?

Recruiter:
...