MAAS CLI returns JSON. jq lets you turn that into readable tables so you can operate comfortably from the terminal.
maas admin machines read | jq -r '(["HOSTNAME","SYSID","POWER","STATUS","OWNER","POOL","VLAN"]
| (., map(length*"-"))),
(sort_by(.hostname)[] | [.hostname,.system_id,.power_state,.status_name, (.owner // "-"), .pool.name, .boot_interface.vlan.name])
| @tsv' | column -t
maas admin machines read | jq -r '.[] | select(.status_name=="Ready") | [.hostname,.system_id] | @tsv'
maas admin machines read | jq -r '(sort_by(.pool.name, .hostname)[] | [.hostname, .pool.name, .zone.name]) | @tsv' | column -t