def is_sensible_roll(dice):
    """Checks the dice results for sensible sizes. Returns a boolean, and an error string if false."""
    if int(dice[1]) > 100:  # Attempted to roll more than 100 dice in a single group.
        return False, "Attempted to roll more than 100 dice in a single group."
    elif int(dice[2]) > 50000: #Attempted to roll a die with more than 50000 sides.
        return False, "Attempted to roll a dice with more than 50000 sides."
    else:
        return True, ""