In short, tool tethering is fall protection for tools. It’s simply ensuring that your tools are secured. It’s a form of insurance in case you accidentally drop or dislodge your equipment. The emphasis with tool tethering is on protecting your colleagues and team – they’re the ones who’ll get injured if you drop tools.
Rock climbers have understood for years that it makes sense to keep all your gear close and tied onto you when you are at height. Dropping tools and equipment is not just inconvenient, but dangerous. So tool lanyards became imperative.