Is it necessary to add an article when there is an adjective modification in front of an uncountable noun, such as have a good time

Is it necessary to add an article when there is an adjective modification in front of an uncountable noun, such as have a good time

You can't say that without the context of the sentence
1. "Clear water" is clear water. Why should we add an article? But if you say "the clear water in that lake is actually toxic", you should add the“
2. In have a good time, time is not "time", but "a period of time", just as in have a beer, beer is not "beer", but "a glass of beer"
Can you understand why we say it's a pleasure to be in now?
In fact, there are all these things in the dictionary. Your confusion is entirely because when you understand an English word, you often understand it according to the first Chinese meaning of the English word?

1. Is the adjective "rain" rainny or directly added with "Y"
When to double write and add Y / ing and other suffixes
2.she could swim when she was five,______
Could't she is can't she?
3. What do the words "what for", "you're right", "that's all right" and "all right" mean?
4.You must look left and right before you______ （cross）the street.
I think we should fill in preposition, so cross, but the answer is cross. Please explain why

You're right that's all right that's all right that's all right that's all right

On English nouns and adjectives
Write nouns and adjectives in English
n. a.
1. Smart
2. Quiet
3. Lively
4. Healthy
5. Friendly
6. Interesting
7. Lucky
8. Strict

I'm very happy. I'm very happy. I'm very happy. I'm very happy. I'm very happy. I'm very happy