Performing many functions exhausted yours truly (3-2-3)
I believe the answer is:
all-in-one
'performing many functions' is the definition.
I don't know anything about this answer so I cannot tell whether this works.
'exhausted yours truly' is the wordplay.
I cannot quite understand how this works, but
'exhausted' could be 'allin' ('all in' can mean exhausted) and 'allin' is located in the answer.
The remaining letters 'one' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Another definition for all-in-one that I've seen is " Combining several functions in a single unit".)