Tool Belt promises to serve a similar role to Bandolier, that is, give you extra slots to hold your stuff. And it's neutral, so anyone can take it! You can even theoretically get multiple bonus slots out of it. Store a couple Pitchfork in there for a rainy day, maybe an empty Chainsaw until you have a good spot to throw it with Act of Desperation or recycle it with Wilson Richards's elder sign. You can even store a Cleaning Kit you don't need yet while you investigate with your Chemistry Set. It could be one hand slot, two hand slots, even six hand slots, wow!
But there are a lot of drawbacks and limitations. You don't necessarily have to go mono-Tool, but if you have non-tools in your slots it's going to be very difficult to swap tools in and out. In fact, it's even difficult to mix one-handed tools and two-handed tools due to the wording of the ability. And there are also potentially timing issues due to the fact the ability costs an exhaust. Here's an example of a series of turns from a recent game that made me want to tear my hair out.
Starting position: Hatchet and Lockpicks in my hands. I'm ready to investigate or help fight.
Turn 1: draw Tool Belt. Cool, I can get my Pitchfork into play and then be ready to take down 5 hp enemies. I play the tool belt and attach the lockpicks to it.
Turn 2: still have my Hatchet in a hand slot, can't play my Pitchfork just yet or I'll drop it. I also can't investigate with my Lockpicks, darn. Attach the Hatchet to the tool belt as well, play my Pitchfork.
Turn 3: Draw the 5 hp enemy I was worried about. Ha ha, I was waiting for this. Except...I can't throw the Hatchet first, because it's on my belt. And if I swap the Hatchet IN, I have to swap the Pitchfork OUT, meaning I won't be able to kill the monster. My practical options are 1) Pitchfork first, grab the hatchet off my belt, defeat the monster, lose my Hatchet permanently, or 2) Pitchfork, spend an action picking up the Pitchfork (possibly provoking), Pitchfork again. Either way, I'm still not investigating with my Lockpicks. This is not what I was hoping for when I built the deck. :X
I'd like the card a lot better if it didn't have the exhaust clause, or if it allowed you to load/unload/swap as many times as you wanted for the one use per turn you get, or if it was straight up just "you have two extra hand slots, which can only be used for Tools." As is, this thing is rough.