Hmm. No idea how to make it bigger. Looks like a bug in either functionality
or documentation.
I entered your text message twice, without returns and it cut off here:
"Does anyone know how to make the screen tip box in Visio larger? It says I
should be able to enter a comment of any length and then cuts half off it
off. Does anyone know how to make the screen tip box in Visio larger? It
says I should be able to enter..."
....which happens to be 255 characters, which sounds like something a
developer would do on purpose.
Last guess: are you talking about shape tooltips or markup comments. Between
Visio 2002 and 2003, they added the markup feature and redefined the word
Comment.
In 2002, a Comment was a "tooltip" for a shape. Now a Comment for the
editing markup, and a shape tooltip is called a "Screen Tip"
Chris Roth
Visio MVP