Harry
Ever since Ximenes (Derrick Macnutt) put it in his 1966 book 'On the Art of the Crossword' they have been considered as unfair.
"... they should not be indirect anagrams, which only give a synonym of the anagram instead of the anagram itself."
Before you complain, Ximenes' book has made the cryptic crossword what it is today and the vast majority of setters follow his guidelines.
Quizmonkey is technically correct, although it is found in a lot of explanations on AB and is hardly worth pointing out.