Can't be anything too big and heavy as I need to store it in the house and then carry it round to the driveway/road when using it. Oh how I long for a double garage with permanent tool cabinet...
I have the same constraint. I feel your pain! I used to have a double garage at my old house, and what a heavenly luxury that was. But life throws us unexpected curve balls and I don't have that perk anymore. It's not just about having the space and dry storage of a garage, it's also a private area to work on the car with your tunes on and a beer on the go. I don't like working on my car outside in the shared car park, in eye shot of my neighbours, who I don't get on with. And obviously outside car jobs are weather restricted, which is also frustrating.
Anyway, I've had to reduce my toolset down considerably as I only have a cupboard under the stairs to store them in.
All you need is a good socket set, and I recommend the biggest Halfords professional set when they do a promotion on them. Apart from that, you only really need torx and triple square sockets to do most jobs on these cars. And a pair of trolley jacks and axle stands.
For any specific tools, ask for a loan on the forum. A few of us have the genuine cam locking tools, polydrive sockets etc etc.
A long 3/4" breaker bar is especially useful for degreeing front and rear hub bolts/nuts after a bearing change.
The old joke that all you need to fix a VW is a 10mm spanner and a hammer isn't actually too far from the truth tbh. You don't need a lot of tools