A set of pliers is the most common tool on a multitool and they usually take up the most ‘real estate’ and are the heaviest of any of the individual tools. Pliers are most common because they are such a useful and versatile tool to have with you.
They can help you do literally hundreds of tasks from tightening a nut to bending a nail or crushing your finger. The last one is not recommended for everyone.
All pliers aren’t the same though. Different types of pliers come with different multi-tools adding to the confusion about which multi-tool you should choose. Multitool pliers are usually either the standard blunt nose pliers or they’ll be needle nose pliers. The blunt nose pliers are great for gripping and squeezing something while the needle nose is better for finer work where you might want to get into a small gap or grab something small and delicate. You’ll need to decide which type of uses are going to be more common to you or take a guess at which type of pliers will be more useful to you.
A lot of tools on your multitool will be able to do more than one thing. So on top of considering the type of pliers, it’s just as important to consider the other tools included on the pliers themselves. The most important are the wire cutters. Of course, they cut wires but they are also useful for snipping off lots of other things. Wire cutters will either be replaceable or they won’t be. If you think you’re going to be using the wire cutters frequently or you want to cut thicker wire, you should really consider a multi-tool with replaceable wire cutters. The replaceable wire cutter blades are cheap to buy and quick and easy to replace with just a couple of screws. They’re probably not essential but if you do use the wire cutters and damage the cutting blade you can't do anything about it if they can't be replaced.
It’ll restrict what you can do with your multi-tool in the future –that’s the opposite of why you have a multitool in the first place.
One last thing to consider when looking at the pliers included, some are spring loaded and some aren’t. If they are spring loaded, it
means you can easily use them with one hand because when you squeeze them shut, they will spring open again in your hand so you can squeeze them again. You get the idea. If they aren’t spring loaded, you might have to use your other hand to manually open them again after you’ve squeezed them. The way I look at it though, having them spring loaded is good but it’s not essential. If I was happy with the other aspects of the plier design and quality and the rest of the multitool functionality suited me, the pliers not being spring loaded wouldn’t be something that stopped me from buying that multi-tool. Spring-loaded is “nice to have” rather than being essential.