Found holes in up-ended can: opened with sharp tool (9)
I believe the answer is:
nitpicked
'found holes' is the definition.
The answer and definition can be both to do with communicating as well as being past participle verbs.
Perhaps they are linked in a way I don't understand?
'up-ended can opened with sharp tool' is the wordplay.
'up-ended' says the letters should be written in reverse (in a down clue, letters go up).
'can' becomes 'tin' (both are metal containers).
'opened with sharp tool' becomes 'picked' (I can't explain this - if you can you should believe this answer much more).
'tin' written backwards gives 'nit'.
'nit'+'picked'='NITPICKED'
'in' is the link.
Can you help me to learn more?
(Other definitions for nitpicked that I've seen before include "Quibbled" , "Made petty criticisms" .)