These translations are unnatural. We do not use "and" in this case, but simply list the adjectives in the right order. For English this would be correct: "I am reading under the tall, beautiful tree". The order is reversed. There are some phrases that use "and" (such as "nice and hot"), but this is generally not used. Notice also the simple and continuous aspects of tense are both acceptable.

why "nice" is not accepted ? If "nice" is szép how would "gyönyörű" be translated ?