A well-placed, strong and evocative adjective can add great detail to a word, phrase or scene. However, too often they come across as contrived and unnecessary.
The beautiful, bubbling river sparkled in the golden sunlight, its silvery ripples reflecting the brilliant, blazing rays that played on the shivering surface.
Too much, far too much. What’s wrong with:
The river sparkled in the sunlight, silvery rays playing on the shivering surface.
(That’s still too much).
And be very careful of ‘broad’ adjectives like ‘beautiful’ in the first sentence. ‘Beautiful’ like ‘nice’, ‘wonderful’, etc. is a broad term – it’s subjective and means different things to different people. It adds nothing so is best avoided, except in dialogue. Also be wary of the thesaurus. It is useful and can help you describe things in a fresh, new way. But be careful. You don’t want to sound like Joey from Friends!