Society writer's petition short and straightforward (6)
I believe the answer is:
simple
'straightforward' is the definition.
(thesaurus)
'society writer's petition short' is the wordplay.
'society' becomes 's' (common abbreviation in names of organisations).
'writer's' becomes 'I'm' ('I am' referring to the writer of the clue).
'petition' becomes 'plea' (petition can mean to plea or beg).
'short' means to remove the last letter.
'plea' with its last letter taken off is 'ple'.
's'+'im'+'ple'='SIMPLE'
'and' is the link.
(Other definitions for simple that I've seen before include "Impels (anag.)" , "Uncomplicated; herb" , "Penniless pie seeker" , "Easy or uncomplicated" , "Plant with medicinal properties" .)