Simplicity - tone of voice guidelines have to be easy for anyone to follow and implement, as lots of employees will write for the brand. Range and flex - you have to provide advice on how to write for the different types of media a brand uses - everything from social to traditional ads in print. And you have to judge how to flex the tone so it is appropriate for different communication tasks, audiences and messages. Launch and training - companies need their people to write well so tone of voice guidelines are often widely distributed. Tone of voice agencies can help launch and train these in. Culture change and values promotion - tone of voice guides are a great way of communicating the brand internally.