Why does $O_{3}$ act as a powerful oxidising agent?

(N/A) Ozone is not a very stable compound under normal conditions and decomposes readily on heating to give a molecule of oxygen and nascent oxygen. Nascent oxygen,being a free radical,is very reactive.
$\mathop {{O_3}}\limits_{\text{Ozone}}$ $\xrightarrow{\Delta }\mathop {{O_2}}\limits_{\text{Oxygen}} + \mathop {[O]}\limits_{\text{Nascent oxygen}}$
Therefore,ozone acts as a powerful oxidising agent.