What species of tree dragon are you talking about?
Most wc specimens of most species are extremely stress sensitive and need a long time for acclimatization. For this period, secure hidings and a calm place are a must. Any manipulation in the tank or any handling should be avoided.
Also most species do need a large water bassin, otherwise they get easily dehydrated.
But in advance of the acclimatization a fecal should be done and the agama treaded accordingly. Most wc Gonocephalus do have a quite heavy prasite load which gets out of balance during the stressful importation and acclimatization.

hope that helps

Ingo