The most common and most likely answer to this crossword clue is the 7 letter word AUTHORS
I've seen this crossword clue in The Sunday Telegraph
A
U
T
H
O
R
S
More clues leading to the result AUTHORS
Buddy explains!

The straight part
We know that "Writes" is the straight/definition part of the clue. The straight part is often a synonym or definition, in this case writes = authors.The cryptic/wordplay part
In cryptic crossword there's often an wordplay/cryptic part as well.This part involves a more complex hint, such as an anagram, homophone, hidden word, etc.
Sadly, We don't have an explanation for this specific crossword clue yet.
What does AUTHORS mean?
AUTHORS noun- The originator or creator of a work, especially of a literary composition.
- Someone who writes books for a living.
- One's authority for something: an informant.
- (sometimes proscribed) To create a work as its author.