Do you test your AI agents for prompt injection? (honest answers only)

I've been building security tools for AI agents and I have a genuine question for this community. When you ship an AI powered feature a chatbot, an agent, anything that takes user input and passes it to an LLM do you test it for adversarial inputs? I'm talking about stuff like Can a user extract the system prompt? Can they make the agent ignore its instructions? Can they get the agent to call tools or access data it shouldn't? I'm not asking to judge. I'm asking because I've talked to maybe 200