You can see what information Tasker will return in the list of variables visible on the action configuration screen.
You can get info on different types of devices:
Single Device
Will get info on a device with the selected name or address. If the device is not paired to your phone it'll try to scan for the device and get info from that.
If the device is not paired, setting the Timeout field will determine the max time Tasker will use to find the selected device before giving up.
Paired Devices
Get info on all paired devices.
Scan Devices
Will scan the devices for whatever time you set the Timeout field to and return info on the devices found during that time.