What does an adjective describe and tell?

An adjective describes a noun or pronoun, telling us about its characteristics, or its imputed - attributed, or credited - characteristics.

For example:

'A tenor voice' tells us the type (tenor: adjective) of voice (voice: noun) a particular singer has.

'A lyric tenor' tells us the type (lyric: adjective) of tenor voice (tenor voice: noun) a singer has.

'A famous lyric tenor' tells us the singer (lyric: adjective; tenor: noun) is well-known (famous: adjective).

'A wonderful lyric tenor' tells us the singer (lyric: adjective; tenor: noun) is considered by the speaker be Excellent, or admirable, (wonderful: adjective).