When is the use of reverse thrust recommended in airline operations?
The main use of Reverse on landing for big-fan engines is to kill the residual forward-thrust rather than to actually supply braking airflow. This offloads the (wheel-)brakes.

If the runway is short, then the wheel-brakes will need assistance to get the aircraft stopped in time, and then you'd use more Reverse. Some aircraft have an Intermediate Reverse click-stop, which allows you to use a standardised mid-level of Reverse; and then there's Full Reverse, but that gets noisy, which some airports don't like (especially at night).

The level of Reverse used is the P1's decision, while complying with aircraft performance on that runway, the airport's noise policy and the airline's balance between engine wear and brakes wear.