Crossword Genius

Declare one's intentions to play straight? (3,4,5,2,3,5)

Ross

I believe the answer is:

put ones cards on the table

I'm a little stuck... Click here to teach me more about this clue!

'play straight?' is the definition.
The definition suggests an adjective which matches the answer.

'declare one's intentions' is the wordplay.
I cannot really understand how this works, but
'one's' could be 'ones' and 'ones' is present in the answer.
This explanation may well be incorrect...

'to' is the link.

Can you help me to learn more?

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