The Merseyside outfit secured the signatures of Mamadou Sakho, Tiago Ilori and Victor Moses on deadline day after acquiring the services of Kolo Toure, Iago Aspas, Luis Alberto, Aly Cissokho and goalkeeper Simon Mignolet.
"It has been a positive transfer window for us." Agger told Danish daily BT.
"We have brought in players with quality and that is what you want. I have not seen all in action yet, but what I have seen thus far is good."
The Reds are currently at the top of the Premier League table due to their 100% record after three games of the campaign.