Solved Commands send only a message with /(the command)

I have a problem: I "created" a command using plugin.yml etc... but when I do the command ( in this case: /souls) in the chat it appears /souls. (any sender)
This is all the plugin code. What's the mistake?

Code:

package it.mnplugin.lupus;

import org.bukkit.Bukkit;
import org.bukkit.ChatColor;
import org.bukkit.command.Command;
import org.bukkit.command.CommandSender;
import org.bukkit.entity.Monster;
import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.entity.EntityDeathEvent;
import org.bukkit.plugin.java.JavaPlugin;

public class Main extends JavaPlugin implements Listener{

    public void onEnable(){
    
        getConfig().options().copyDefaults(true);
        saveConfig();
        Bukkit.getServer().getPluginManager().registerEvents(this, this);
        getServer().getConsoleSender().sendMessage(ChatColor.AQUA + "MagikNova " + ChatColor.DARK_AQUA + getConfig().getString("version") + ChatColor.AQUA + " enabled" );
        getConfig().set("souls", 33);

    }

    public void onDisable(){
    
        getServer().getConsoleSender().sendMessage(ChatColor.AQUA + "MagikNova " + ChatColor.DARK_AQUA + getConfig().getString("version") + ChatColor.AQUA + " disabled" );
        saveConfig();
    
    }

    @EventHandler
    public void onEntityDeath(EntityDeathEvent e){
    
        if(e.getEntity() instanceof Monster){
        
            Monster mdeath = (Monster) e.getEntity();
        
            if(mdeath.getKiller() instanceof Player){
            
                getConfig().set("souls", getConfig().getInt("souls") + 1);
                saveConfig();
            
            }
        
        }
    }

    public boolean onCommand(Command cmd, CommandSender sender, String label, String[] args){
    
        if(cmd.getName().equalsIgnoreCase("souls")){
        
            sender.sendMessage(ChatColor.AQUA + "(!)You have" + ChatColor.LIGHT_PURPLE + getConfig().getString("souls") + ChatColor.AQUA + "Souls!");
        
        }
    
        return false;
    
    }

}

The plugin.yml looks like:
name: MagikNova Plugin
version: 0.0.1
main: it.mnplugin.lupus.Main
description: Enjoy the Magic....

commands:
souls:
usage: /souls
description: states your current Soul balance

The file is the screenshot of the problem

 

@timtower I tried to change return false; to true but I have the same problem

 

@timtower I created a command maybe 4 weeks ago, and it had the same problem. Then I formatted the PC and now I re-installed the new eclipse version. Maybe I mess up with something in eclipse, why I has the same problem (now and 4 weeks ago) that the javadoc doesn't do anything, I validated it, applied it, but it continue to say me: "this element has attached....". Another problem is that when I use econ.withdrawPlayer() (Vault) it doesn't work and in eclipse it says that "the metod is deprecated" and to add SuppressWarning (obviously, if I add it it doesn't work to ) I hope it's eclipse, because in the web I found someone with my same problem. If not, I have Windows 7 (seven ice, exactly) with 32bit, but I hope it's not my computer

 

I solved it, I have copy-pasted an internet code and I editd it