I have some <a href="#blah"></a> elements, and I'd like more control over what is displayed on hover - something better than "Go to page 2". Is this possible?

I haven't found a way to do this. PDF link annotations don't have any tooltip field, and the "Contents" field that they do have for alternate text appears to be ignored by every PDF viewer that I tried. Acrobat doesn't even seem to give any tooltip for links unless they are external links.