Tool?  I guess there is a special tool, but I just used end cutters such as
the
http://www.channellock.com/acb/stores/1/356_-_6_inch_End_Cutter_P121C9.cfm?UserI
D=115466&jsessionid=8230bf991f22272e7d30
to tighten the band that secures the CV boot.  They were also very handy to
remove the bands from the old boot.  Obviously a different level of force
was used for removal than for tightening.  Some electrical tape over the
cutters provides protection from cutting though if you feel the need for
increased clamping force.

The clearance is quite tight for the larger band, so I wouldn't chance the
worm drive of the clip getting caught on something.

Walt Kienzle
1991 9000T

You might be surprised how inexpensive the tool is for those clamps.  I
bought one at a local parts chain store (forget if Pep Boys or Auto
Zone) for the boot clamps on a steering rack (same kind of clamps).

Yes, many hack mechanics will use plastic cable ties (zip ties,
ty-wraps, etc.)  The problem is they are plastic and have a short life
span before they break (unknown to you).  Then whatever it is you are
trying to keep covered by the boot will be hanging out in the open.

Since you used the term "jubilee clip" and not hose clamp, I'll assume
you are in the UK.  Here's a link to some tools near you for comparative
prices.  I bought the plier style tool.

http://www.justoffbase.co.uk/s.nl/sc.9/category.125/.f

Besides, it's another great excuse to buy some cool tools!  ;-)