/mcstats - View your mcMMO stats
/<skill>- View detailed information about a skill
/mctop <skill> <page> - Leaderboards
/inspect <player> - View detailed player info
/mcability - Toggle ability activation with right click
/party Check party information.
/party create <party-name> <password> Creates a new party
/party join <player> [password] Join a players party
/party invite <player> Invite a player to join your party.
/party accept <player> Accept a party invite
/party password <password> Set a password for the party you currently own.
/party kick <player-name> Kick a player from the party.
/party owner <player-name> Set a player as the party owner.
/party expshare [none/equal] Set the party share mode.
/party lock Lock the party
/party unlock Unlock the party
/party quit Quit the party you're currently in.
/party help More information about parties.
/partychat [message] Allows you to communicate with other players in your party.
Power Level: This is a total for all of your skills. You level up in Mining, your power level will also increase.
Excavation: Using a shovel on Dirt, Grass, Gravel, Sand and Clay.
Mining: Mining stone and ores using a pickaxe.
Fishing: Find a water source and throw your fishing line into it and catch some fish, possibly tools and armor.
Unarmed: Hitting passive and hostile mobs with your bare fists(empty hands). Your damage will increase as you level up.
Acrobatics: Taking fall damage and not dying will increase your level.
Swords: Hitting passive and hostile mobs with a sword.
Herbalism: Collecting herbs and plants. (farming)
Repair: Using wood planks to repair wood tools, cobblestone to repair stone tools, etc.
Woodcutting: Cutting down trees, comes with treefeller which helps clear out large trees in one swing.
Alchemy: Brew potions and you will unlock custom potions as you progress!
Archery: Shooting passive and hostile mobs with your bow.
Axes: Hitting passive and hostile mobs with an axe.
Taming: Taming mobs or combat with your wolves.
With mcMMO to use the abilities, you will need to press your Left Shift key and right click to activate abilities.
The way I see it, yes may be a little annoying but it makes it so that if you accidentally right click, you aren't wasting the ability.
You can look into the abilities in game by type the /<skill> for more information.