too aggressive (especially on the river)?

[subq]

Is this too aggressive on the river?

Paradise Poker 0.50/1 Hold'em (8 handed)

Preflop: Hero is MP1 with A[img]/images/graemlins/diamond.gif[/img], 9[img]/images/graemlins/diamond.gif[/img].
UTG folds, UTG+1 calls, Hero calls, MP2 calls, CO folds, Button calls, SB folds, BB checks.

Flop: (5.50 SB) 9[img]/images/graemlins/club.gif[/img], Q[img]/images/graemlins/diamond.gif[/img], 4[img]/images/graemlins/diamond.gif[/img] <font color="blue">(5 players)</font>
<font color="CC3333">BB bets</font>, UTG+1 calls, <font color="CC3333">Hero raises</font>, MP2 calls, Button folds, BB calls, UTG+1 calls.

Turn: (6.75 BB) 5[img]/images/graemlins/diamond.gif[/img] <font color="blue">(4 players)</font>
BB checks, UTG+1 checks, <font color="CC3333">Hero bets</font>, MP2 calls, BB folds, UTG+1 calls.

River: (9.75 BB) 6[img]/images/graemlins/diamond.gif[/img] <font color="blue">(3 players)</font>
UTG+1 checks, <font color="CC3333">Hero bets</font>, <font color="CC3333">MP2 raises</font>, UTG+1 calls, <font color="CC3333">Hero 3-bets</font>, <font color="CC3333">MP2 caps</font>, UTG+1 calls, Hero calls.

Final Pot: 21.75 BB
<font color="#990066">Main Pot: 21.75 BB, between UTG+1, Hero and MP2.</font> &gt; <font color="white">Pot won by MP2 (21.75 BB).</font>

Results in white below: <font color="white">
UTG+1 shows Kd Qc (flush, king high).
Hero shows Ad 9d (flush, ace high).
MP2 shows 7d 8d (flush, ace high).
Outcome: MP2 wins 21.75 BB. </font>