Over the years there have been tons and tons of different pickup designs and style made by many different manufacturers. Some guitar manufacturers use single coil pickups while others use a humbuckers. Some guitar companies have decided come up with their own style of pickups. There is only one commonality amongst all electric guitar pickups: they all eventually need to be adjusted. That is where a guitar pickup screwdriver kit comes in handy.
Although there is no such thing as a guitar pickup screwdriver kit, many guitar pickups require small screwdrivers that don't typically come in your average screwdriver set. Many guitar pickups require micro screwdrivers to raise and lower the height of the pickups. You may also need these smaller screwdrivers to remove the pickup ring around the pickup or the pickguard. Micro screwdrivers are used for many repairs on guitars other than pickup repairs. Micro screwdrivers are usually needed to remove the truss rod cover on the headstock before adjusting the truss rod. Micro screwdrivers are also used to remove the cavity covers on the back the guitar body. Without these small screwdrivers, it would be impossible to do these guitar repairs.
You can't have a guitar repair bench without these tools. I don't even think you can own and play a guitar without these tools. You need micro screwdrivers just to adjust a guitar's truss rod. Plus, these tools are just good all around tools to have for other repairs. Personally, I like to buy Craftsman screwdrivers because they have a lifetime warranty. You can buy whatever brand name screwdrivers you like. Just make sure you get a set. If you would like more information about how to adjust your guitar pickups, please see my how to repair guitar pickups article.