What is a word to describe inefficient communication?

Solution 1:

Taking a page from Araucaria, I'd suggest long-winded:

using too many words in speaking or writing
_{from m-w.com}

So you could say, for example:

I don't like such long-winded resumes.
He gave a really long-winded answer to what I meant as a simple question.
Pat's long-windedness can be really off-putting.

Solution 2:

Using the word verbose may work for you, for example:

"For a 1 mark question, your answer was verbose."

As antonyms, you could use laconic or concise, e.g.

"Credit will be given for a concise description of the problem."

Solution 3:

Adding to other good suggestions, when someone uses too many (unnecessary) words for a simple description, the adjective wordy could be used which means:

Using or expressed in rather too many words: 'a wordy and repetitive account'

[Oxford Online Dictionary]

Example: Is your resume too wordy? and Ways to Tighten the Too-Wordy Resume

Solution 4:

Some great answers here.

In engineering we would say that the resume had a low signal to noise ratio. It's a fairly derogatory term for something or someone that is unnecessarily verbose.

Solution 5:

Such long-winded communication may be described as prolix. Here is the definition from the Merriam-Webster Dictionary:

Full Definition of prolix

1: unduly prolonged or drawn out : too long

2: marked by or using an excess of words

Examples of prolix in a sentence

The speech was unnecessarily prolix.

< a person known for habitually transforming brief anecdotes into prolix sagas that exhaust their listeners >

The noun form of this word is prolixity. You could say for example that you disapprove of prolixity in resumes.