new AI agent just got API access to our stack and nobody can tell me what it can write to

Got pulled into a meeting today. apparently we're adding an Agentic AI to the team. it will learn our environment, handle tasks autonomously, and integrate via API. it does not need onboarding, a desk, or health insurance. Great. i have one question nobody in that meeting could answer. how does it actually work? not philosophically. like what is the system. because from what i can tell it's an LLM with tools strapped to it, some kind of memory layer nobody can fully explain, and a control loop that lets it run without a human saying yes to every step.