Poultry shears have classically been used for tasks like cutting a chicken in half down the breastbone, although a cleaver can also be used for this purpose. They can also be used on an assortment of tough foods to cut rapidly and with a great deal of control. You may note that specific recipes call for poultry shears in particular for things like trimming and cutting meat. Ideally, the shears should not be used for non-kitchen tasks like cutting carpeting, although most shears are perfectly capable of being used in this capacity.
When seeking out poultry shears, it pays to spend a little more. Cheap ones will ultimately fail, possibly at a very awkward moment, and you may find them frustrating and irritating to use. Look for solid shears which feel heavy and well balanced in your hand, and avoid poultry shears with materials that feel flimsy or shoddy. You should also stay away from shears with lots of nooks and crannies, as these can harbor bacteria.
Care for poultry shears like you would care for any other blade. When not in use, keep them wrapped or in a knife rack to protect the blades and to prevent injuries. After use, hand wash the shears with very hot water and soap; a few drops of bleach may be used periodically to keep bacteria off the shears. Never run kitchen shears of any kind through the dishwasher, as this can dull the blade and damage the handle.