set interfaces bridge br0 stp
set interfaces bridge br0 member interface eth0 cost 1000
set interfaces bridge br0 member interface eth0 priority 32
commit

vyos@vyos# bridge link show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br0 state learning priority 32 cost 1000

set interfaces ethernet eth0 description "test"
commit

vyos@vyos# bridge link show dev eth0
2: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 master br0 state forwarding priority 32 cost 32