On a shared path, a cyclist usually travels faster than someone walking. Announcing an approach helps, but a bell does not itself make an overtake safe. When people are ahead, slow down first and judge whether there is room to pass calmly.
If approaching from behind, ring early enough to avoid startling someone at close range. Even then, a person may not hear the bell or immediately know which side the bicycle is on. Bends, junctions and places with a restricted view call for particular care.
Where the path narrows, waiting is better than squeezing through. Passing needs enough lateral space and a speed that leaves time to stop if someone changes direction unexpectedly. A good bell helps communication; patient riding makes the signal useful.