One has to pretty much be at the end of one's line to want to hyphenate words in the middle when they don't already have hyphens. Literally and figuratively at the end of the line. People used to have to know how to break words effectively back when we were all using typewriters to produce business documentation--do you remember in typing class learning about the maximum number of spaces to leave at the end of a line without it looking stupid and then figuring out the appropriate place to hyphenate a longer word, but to never hyphenate a word with fewer than so many letters even if it had more than one syllable? There were entire dictionaries published with nothing in them but proper hyphenation locations. Sometimes picking the hyphenation spot was not as obvious as one might have thought.
Today, with the wonders of proportionally spaced fonts, most of us never have to worry about hyphenating words; we don't care whether there's space at the end of the line. But we poor technical writers (or anyone publishing actual documents) still need to make the work look professional, which still means not leaving huge empty areas at the end of a line (when left justifying) or between words (with automated right/left justification).
Luckily for us, most good desktop publishing tools allow you to set your hyphenation preferences. For example, you can turn it off entirely. This is safe but not always pretty. You can specify the minimum word size to hyphenate when needed, although it usually has a good default.
But there are some things that software just has a rough time with. The other day, when reviewing my earlier writing, I found this word break:
[text filling up the line and then ] rear-
An astute reader soon realizes that this was just a bad hyphenation choice for "rearrange," but it takes a moment of thought. There has been much speculation on what "rear range" might refer to, but I think I shall leave that as an exercise for the reader. My point is simply: Don't rely on automatic hyphenation to be correct, any more than you rely on your spell-checker to give you the correct spelling or to find incorrect words.
I posted another silly example in Irish Noir.