Ok... let's have a look at your first body paragraph;
First of all, the tour is planned by the travel agency so I just enjoy my trip.
What is the reason behind this justification? It is that you do not need to put effort for planing your trip and you can simply hand over that to a third party and enjoy your tour. So, give more emphasis to your reason;
First of all, arranged tours are very convenient and comfortable since the travel agent looks after the part of planning the tour and meeting all travel needs with regard to accommodation and transportation.For example, I booked a tour to DaLat last year in a designed tour. I only needed to pay money to the travel agency and then I would have the plan and the rout. I had a wonderful trip and did not think about where to go and what to eat. The trip lasted for four days and I went to many famous interesting places in DaLat such as the Love Valley, the city flower garden, etc. My experience of going in a packed trip shows that going in a trip which is planned by the tourist company is the best way to feel relaxed during the tour.
This is a very good example, but I feel you should not go into such detail. The reason is that you need to manage time and if you drag on one idea it may not help you with time management. So, skim the essential part that you need to tell.