After your comment I dowloaded WTP. I had already WTP in (actually saying "WST XML UI" in Manage Configuration) but was unable to use it (XML editor hangs). Also have a message saying "XML editor (locked by content type)" in the editor associations preferences. So Googled for it and find something explaining that I have to dowload all the stuff (argh 210 Mo...).
So I will not use it, though perhaps I will try, I'm too curious
Thanks for your suggestion but it's too complicated so I tried with simple-method token which have a documentation (and actually my concern here is more for simple-methods.xsd) . I'm now sure that IntelliJ is not working properly with XML documentation during completion : same message than above while there is a documentation for this token in simple-methods.xsd.
Conclusion of my searches about IDE or IDE/plugins couples aware of documentation during XML completion :
XMLBuddy : not
WTP : not
Oxygen : yes
Netbeans 5.5 : not (but I'm not a specialist, perhaps there are plugins ?)
IntelliJ 6.02 : not (but I'm not a specialist, perhaps there are plugins ?)
So it seems that for now we must only relay on Eclipse 3.2/Oxygen for functionnality. Moreover it cost at least US$ 64(temporary promo to US$ 48 apart).
So what people think about all that ? Are we sure that we must constraint people to use this tools (Eclipse/Oxygen) ?
Of course if in the future maybe some enhancement will be found for this in IDE or plugins but today that's the situation. I will be happy to be corrected of course...
I thing that this is really important, please give your opinions or advices.