Just posted a tanto off to the US with UPS..
As for descriptions. Online, you get 2 to fill in, one for the packing label which can only be short and a rather lengthy gap for the customs invoice which lets you go into great detail. The label description being short, your kind of limited. Having attempted to follow the "non vague and accurate" guideline then the best i could do there is "Japanese artwork tanto", followed by a more lengthy description in the customs invoice which included "traditionally forged cultural artwork by such and such, made from steel and in wood sheath, year 2007" , along with the customs tariff number.
Had a few issues this time with their website and the pick up where they totally ignored my scheduled pick up time of no earlier than 2.30 pm as i wasn't home from work. Yesterday, waited all day with a no show so i called them and they said they arrived earlier than anticipated and apologised. Rearranged for today and they show up at 10.30 am instead of the agreed 2pm. Luckily off work with a cold so didn't miss them. Had a bit of a moan to the driver who just apologised and said they were busy.
The other issue, their website. It didnt like to keep the information with the booking. I could not retrieve my online filled in customs form so had to print a PDF off their website and fill it out by hand. It does state when you print your package label out that they require 3 printed customs invoices. I called UPS and they were not much help but did say the written invoice should be fine. The call centre is in the US, i think they struggle with my accent.
Last time i had no problem printing out the customs invoices, i should add.
Anyways, info put here for folks that may want to use UPS, hope it helps.