Whenever I ask a question, I end with "please, tell me."

But somebody told me as an answer like this:

(answer)By now, you should know that in English it's more polite to ask: I'd like to know... OR Can you please tell me ... Your requests tend to sound rude.

Is it so rude to say like " please, tell me."?

Whenever I ask a question, I end with:

... please, tell me.

But somebody told me as an answer like this:

By now, you should know that in English it's more polite to ask: I'd like to know... OR Can you please tell me ... Your requests tend to sound rude.

Is it so rude to say please, tell me?