Be annoyed, but prepare to do some darning for? (3,3,6)

'do some darning for?' is the definition.
I don't know anything about this answer so I can't judge whether it can be defined by this definition.

'be annoyed but prepare' is the wordplay.
I cannot really understand how this works, but
'be' could be 'need' (needing is a kind of being) and 'need' is found in the answer.
'prepare' could be 'get' (I've seen this in another clue) and 'get' is located in the answer.
This may be the basis of the clue (or it may be nonsense).

'to' acts as a link.

Can you help me to learn more?