Tone refers to the author's attitude or approach toward the subject matter or the audience in their writing. It can convey emotions, opinions, and feelings through word choice, style, and overall feel of the text. The tone can be formal, informal, serious, humorous, sarcastic, optimistic, pessimistic, and many others, depending on the context and the writer's intent. The tone is important because it helps to set the mood and influences the reader's perception and interpretation of the text.
In contrast, a word that has more than one meaning depending on the context is referred to as a homonym or polysemy, which is different from the concept of tone.
So, the correct understanding of "tone" would align more with "The words a writer uses in their text to support their purpose."