package seedu.ezdo.commons.core;

/**
 * Container for user visible messages.
 */
public class Messages {

    public static final String MESSAGE_UNKNOWN_COMMAND = "Unknown command";
    public static final String MESSAGE_INVALID_COMMAND_FORMAT = "Invalid command format! \n%1$s";
    public static final String MESSAGE_INVALID_TASK_DISPLAYED_INDEX = "The task index provided is invalid";
    public static final String MESSAGE_TASKS_LISTED_OVERVIEW = "%1$d tasks listed!";

}

package seedu.ezdo.commons.core;

/**
 * Container for user visible messages.
 */
public class Messages {

    public static final String MESSAGE_UNKNOWN_COMMAND = "Unknown command";
    public static final String MESSAGE_INVALID_COMMAND_FORMAT = "Invalid command format! \n%1$s";
    public static final String MESSAGE_INVALID_TASK_DISPLAYED_INDEX = "The task index provided is invalid.";
    public static final String MESSAGE_TASKS_LISTED_OVERVIEW = "%1$d tasks listed!";
    public static final String MESSAGE_WRONG_LIST = "Please return to the task list if you want to mark a task as done.";

}

Add punctuation to messages to improve consistency
Add punctuation to messages to improve consistency
