Overplayed or just right?

As we have learned in a previous episode I have tended to be a little tight/passive. I think I have begun making good progress, but I want to make sure that I'm on the right track. Any feedback on this hand or hands like it are appreciated.

I feel like I played it well, but I don't know if I should've called extra bets on the river.

Party Poker 0.50/1 Hold'em (10 handed) FTR converter on zerodivide.cx

Preflop: Hero is CO with K[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/club.gif[/img]. MP1 posts a blind of $0.50.
[color=#CC3333]UTG raises</font>, [color=#666666]2 folds</font>, [color=#CC3333]MP1 (poster) 3-bets</font>, MP2 calls, [color=#666666]1 fold</font>, [color=#CC3333]Hero caps</font>, [color=#666666]3 folds</font>, UTG calls, MP1 calls, MP2 calls.

Flop: (17.50 SB) 6[img]/images/graemlins/club.gif[/img], A[img]/images/graemlins/spade.gif[/img], 7[img]/images/graemlins/club.gif[/img] [color=#0000FF](4 players)</font>
[color=#CC3333]UTG bets</font>, MP1 calls, MP2 calls, [color=#CC3333]Hero raises</font>, UTG calls, MP1 calls, [color=#CC3333]MP2 3-bets</font>, [color=#CC3333]Hero caps</font>, UTG calls, MP1 calls, MP2 calls.

Turn: (16.75 BB) 3[img]/images/graemlins/spade.gif[/img] [color=#0000FF](4 players)</font>
UTG checks, MP1 checks, [color=#CC3333]MP2 bets</font>, Hero calls, UTG calls, MP1 calls.

River: (20.75 BB) J[img]/images/graemlins/spade.gif[/img] [color=#0000FF](4 players)</font>
UTG checks, MP1 checks, [color=#CC3333]MP2 bets</font>, Hero calls, UTG calls, MP1 folds.

Final Pot: 23.75 BB