需要缩短函数输出文本的长度

I am a newbie. Figured out how to show property descriptions on property preview pages, but I want to only show a portion of the description, to cut it off and add to be continued dots ...

Few questions:

  1. Is this the best way to display a property description?
  2. How do you shorten the amount of text displayed?
  3. How do you add the dots at the end?

This successfully displays the property description, however, I don't know where to start in shortening it and adding dots.