What is most important to consider when choosing an appropriate tone for your technical writing?

Tone in writing a documents refers to the character or attitude of the writer towards his/her readers. Lot of things to consider in writing a document such as the following questions who are my readers?, what is the purpose of my documents?, what approach should I use? and most importantly what tone should I use?. By securing a checklist of these items, absolutely, the writer can produce an appropriate documents or achieve a good technical writing skills.