Writer's captivated by Depp, too — made up like a tart? (4-6)

I believe the answer is:

open-topped

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'tart?' is the definition.
Both the definition and answer are adjectives.
Maybe you can see a link between them that I don't see?

'writer's captivated by depp too made up' is the wordplay.
'writer' becomes 'pen' (something which writes).
'captivated by' is an insertion indicator.
'made up' indicates an anagram.
'depp'+'too'='depptoo'
'depptoo' anagrammed gives 'otopped'.
'pen' inserted within 'otopped' is 'OPEN-TOPPED'.

'like a' acts as a link.

Can you help me to learn more?

I've seen this clue in The Guardian.

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