It's worth getting to grips with tone of voice as an important part of branding.
Tone of voice is not what you say, but how you say it. In business, confusingly, tone of voice has to do with our written communication.
Tone of voice delivers your brand personality. "To engage your audience emotionally, you must let your brand's personality show" ( http://amzn.to/2ubIk7X ).
So, what is your brand personality? Are you communicating that? What needs to change?
Getting everyone to agree on a tone of voice enables you to communicate it consistently.
Having done that groundwork, you can then answer questions such as:
Should we use jargon?
Can we use humour?
How informal can we be?
What punctuation should we use?
What do our competitors sound like?
Get it done by: http://johnallsopp.com
For: .. if you're not sure about your brand personality, maybe defining your brand values will help (free)