Energetic secret agent takes a nap inside (6)

I believe the answer is:

snappy

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

'energetic' is the definition.
(similar in meaning)

'secret agent takes a nap inside' is the wordplay.
'secret agent takes' becomes 'spy' (I am not sure about this - if you are sure you should believe this answer much more).
'inside' means one lot of letters goes inside another.
'spy' placed around 'nap' is 'SNAPPY'.

Can you help me to learn more?

(Other definitions for snappy that I've seen before include "Bad-tempered" , "Irritable, curt; stylish" , "Ratty" , "Irritable - smart" , "Cleverly concise; stylish" .)

I've seen this clue in The Globe and Mail.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.