Team observe them making annotation (8)

I believe the answer is:

sidenote

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

'them making annotation' is the definition.
I know nothing about this answer so I can't tell whether this works.

'team observe' is the wordplay.
'team' becomes 'side' (both can mean a sports team).
'observe' becomes 'note' (synonyms).
'side'+'note'='SIDENOTE'

Can you help me to learn more?

(Other definitions for sidenote that I've seen before include "I could be pencilled in for the wing" , "Marginal comment" .)

I've seen this clue in The Irish Times.

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.