When warlock chooses a pact with The Great Old One, he gains a feature called Awakened Mind:
Starting at 1st level, your alien knowledge gives you the ability to touch the minds of other creatures. You can communicate telepathically with any creature you can see within 30 feet of you.
My question is, is the communication two-ways, or only one-way?
I assume it's only one-way: I can "send" messages to target creature's mind but I can't receive any responses. So it's not possible for this creature to "send" me back any thoughts or messages and I can't read any of the creature's thoughts.
It was brought to my attention in comments, that the wording of the Warlock's Awakened Mind feature was changed in the latest printing. Before it was: "You can communicate telepathically with any creature" but now it is:
"You can telepathically speak to any creature"
Which is suggesting clearly to me that this is only one-way communication.
From Wizards' July 2015 Sage Advice column: