In my curses agent was very good with other fast mana in a vacuum. Field of Ruin raises the floor of the card significantly if you can afford the land.

However without other mana denial or creatures it didn't fit well in the deck; it turned on all the opponents removal, it had no support so the beater value was minimal, and the mana denial effect didn't have enough backup to matter. In a DGA deck those cons are not present and so has a lot of promise.