What does the cryptic crossword clue "A helper, temp, upset one writing booklets? (11)" mean?

The wordplay uses an anagram. anagram of A + HELPER, + TEMP, = PAMPHLETEER The answer is PAMPHLETEER.

A helper, temp, upset one writing booklets? (11)

Daily Mail Cryptic #17196 | 19 Across | 2023-09-29 flower