Half-rate agent far from smooth (5)

I believe the answer is:

raspy

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'far from smooth' is the definition.
I can't judge whether this definition defines the answer.

'half-rate agent' is the wordplay.
'half' suggests halving the letters.
'agent' becomes 'spy' (spy is a kind of agent).
'rate' cut in half is 'ra'.
'ra'+'spy'='RASPY'

Can you help me to learn more?

(Another definition for raspy that I've seen is " Harsh, grating".)

I've seen this clue in the Sydney Morning Herald.

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