Is honest in conveying the entertainment’s not very good (5,4)

I believe the answer is:

plays fair

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'is honest in conveying' is the definition.
I know nothing about this answer so I cannot tell whether it can be defined by this definition.

'entertainment's not very good' is the wordplay.
'entertainment's' becomes 'plays' (I can't explain this - if you can you should give a lot more credence to this answer).
'not very good' becomes 'fair' (I've seen this in another clue).
'plays'+'fair'='PLAYS FAIR'

'the' is the link.

Can you help me to learn more?

I've seen this clue in the Evening Standard.

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