Decide Whether to Mulligan an Opening Hand in a Trading Card Game

The clock is ticking, the hand is borderline, and the group is waiting. This takes your actual cards, your deck's game plan, and your seat, then gives a one-word keep or mulligan call with the two sentences of reasoning behind it, no waffling about how it depends.

My opening hand in {GAME_NAME} is: {HAND_CONTENTS}. My deck's plan is [aggro curve out by turn 4 / control with removal and a late-game finisher / combo needing 3 specific pieces], and I am on the [play / draw].

Tell me straight whether to keep this hand or mulligan, based on: whether it can execute the deck's core plan without drawing into more pieces, how many turns it survives if I draw nothing relevant, and how this specific matchup changes the calculation if I know my opponent's deck.

Give a one-word decision (keep or mulligan) followed by two sentences of reasoning. No hedging.