Lanyard

Most fishing tools are used one-handed, over water, while the other hand holds a fish. That is the exact set of conditions under which things get dropped. A coiled lanyard clipped between the tool and a belt loop, a D-ring or a sheath means a dropped pair of pliers dangles instead of sinking.

Coiled cord is the common design because it stays short until you need reach and then extends. Look for a proper clip at both ends rather than a split ring, which will work its way open.

Nets, grippers, line clippers and phones all benefit from the same treatment.

There is a real safety argument against tethering yourself to anything in moving water or on a boat, so most lanyards use a quick-release buckle or a magnetic clip that separates under load.