The meeting document spells out the process in a much blunter way than Amazon's cutesy marketing suggests.

"[Astro] slowly and intelligently patrols the home when unfamiliar person are around, moving from scan point to scan point (the best location and pose in any given space to look around) looking and listening for unusual activity," one of the files reads. "Vesta moves to a predetermined scan point and pose to scan any given room, looking past and over obstacles in its way. Vesta completes one complete patrol when it completes scanning all the scan point on the floorplan."

Developers who worked on Astro say the versions of the robot they worked on did not work well.

"Astro is terrible and will almost certainly throw itself down a flight of stairs if presented the opportunity. The person detection is unreliable at best, making the in-home security proposition laughable," a source who worked on the project said.

"They're also pushing it as an accessibility device but with the masts breaking and the possibility that at any given moment it'll commit suicide on a flight of stairs, it's, at best, absurdist nonsense and marketing and, at worst, potentially dangerous for anyone who'd actually rely on it for accessibility purposes," the source said.