An AI agent doesn't break into anything. It logs in with a credential somebody gave it and uses the same web calls every other app uses. To a security tool watching the network, that's a normal day. The only place the agent's own choices show up is in telemetry the agent emits about itself.
What useful agent telemetry contains
Which agent ran, and under which identity
Every tool it called, with the arguments it chose
What each tool sent back, since that's what shaped the next step
Which request started the run, so one session can be followed end to end
Where the run stopped, and whether a person cleared it
Where teams get it wrong
They assume existing tools already cover it. The SIEM is collecting and the cloud logs are on, so surely the agent is watched. Those tools record that an API call happened under a valid credential. They don't record that an agent decided to make it, or what it read on the way there.
Here's a concrete one. An agent with a read credential pulls fourteen customer records over an afternoon. Every single call is allowed and every one looks like the app doing its job. The pattern only reads as wrong if something recorded that one agent, in one session, made all fourteen calls. Without that, there are fourteen ordinary log lines and no story connecting them.
The checkpoint has to sit between the agent and the tools it calls. That's the one spot where agent behavior is still visible as agent behavior.