By description, I assume you mean comment.
Try these two CLI commands from
mgmt_cli -r true --format json show group name group-name details-level full | jq '.members[] | [.name , ."ipv4-address" , .comments ] | @csv'
mgmt_cli -r true --format json show group name adult-machines details-level full offset 500 | jq '.members[] | [.name , ."ipv4-address" , .comments ] | @csv'
Note that a second command is required since the API will only return 500 results at a time. The "offset 500" will return the next set of results.