In the diary of Samuel Pepys what is the tone?

In my opinion, very reliable. He intended it only for himself, thus did not have an audience to impress.

Pepys diary was so important because there was a lot of important evidence and detail about the great fire and the plague, which is still useful now

no, he preserved it and after he died it was kept in a library

inform other about important events

i think because he was very good man