I have bought tools from the US several times, and I have been charged VAT and customs duty most times. It is a bit unpredictable though - with one shipping company I was charged every time, with another I was charged two times out of three, with another I wasn't charged at all. I couldn't see any pattern to it, it looked like it was just pure luck (for my wallet) when I did not get charged.
Also, the method of charging varies too. FedEx (as far as I can recall) always invoiced me a couple of weeks after delivery - the invoice comes as a surprise the first time it happens. ParcelForce (local delivery agents for UPS) require that you authorise the release of your parcel through customs, via their website (they send you a postcard, in the post, which contains the relevant info for when you access their website - by releasing the goods you are consenting to pay the charges which are listed on the postcard), and then you have to pay them when they call to the door before they hand you your goods.
In every case, for me, the cost of the tools, including VAT and customs duty, was still cheaper than buying those tools here (although in many cases the same tools were just not available here).