The "concise" in "Writing clear, concise, sentences" is a non-restrictive adjective, tacked on as secondary information, and spoken between two pauses, with a d

The "concise" in "Writing clear, concise, sentences" is a non-restrictive adjective, tacked on as secondary information, and spoken between two pauses, with a different pitch to the other 3 words. The sentence could mean the speaker or author thinks sentences must be concise to be clear. The "concise", like the "clear", in "Writing clear concise sentences" is a restrictive adjective, primary to the meaning of the sentence, with all words spoken at the same pitch. Clarity and conciseness are orthogonal. Perhaps there's a slight pause between clear and concise, which could be shown with a single comma.