You can use CommandBlock to block commands in certain worlds, globally, assign permissions to commands who don't have any or simply customize the no permissions message.

Features

Easy to use ✓
Highly customizable ✓
Lightweight and failsafe ✓
Per world command blocking ✓
Assign permissions to commands ✓

Commands and Permissions

Command	Permission	Default	Description
/commandblock	commandblock.help	true	Shows the help screen
/commandblock (enable/disable)	commandblock.toggle	op	Toggles the plugin
/commandblock consolewarnings (enable/disable)	commandblock.consolewarnings	op	Toggles the consolewarnings
/commandblock prefix (enable/disable)	commandblock.prefix	op	Toggles the prefix
/commandblock prefix set (prefix)	commandblock.prefix	op	Modifies the prefix
/commandblock message set (message)	commandblock.add	op	Modifies the no permissions message
/commandblock alternativemessage set (message)	commandblock.message	op	Modifies the alternative no permissions message
/commandblock defaultmessage set (message)	commandblock.message	op	Modifies the default message used in /cmdblock add
/commandblock add (command)	commandblock.add	op	Adds a command to the config
/commandblock remove (command)	commandblock.remove	op	Removes a command from the config
/commandblock set (command) permission (permission)	commandblock.set	op	Modifies the permission of a command
/commandblock set (command) message (message)	commandblock.set	op	Modifies the message of a command
/commandblock block (command) (world)	commandblock.block	op	Blocks a command from a world
/commandblock unblock (command) (world)	commandblock.block	op	Unblocks a command from a world
/commandblock info (command)	commandblock.info	op	Shows info about a command
/commandblock reset	commandblock.reset	op	Resets the config
/commandblock clear	commandblock.clear	op	Empties the command list in the config
/commandblock list	commandblock.list	op	Lists all the commands on the config
/commandblock reload	commandblock.reload	op	Reloads the config
/commandblock about	commandblock.about	op	Shows information about the plugin
N/A	commandblock.bypass	false	Permission to bypass the plugin

Metrics

This plugin utilizes Hidendra's plugin metrics system, which means that the following information is collected and sent to mcstats.org:

A unique identifier
The server's version of Java
Whether the server is in offline or online mode
The plugin's version
The server's version
The OS version/name and architecture
The core count for the CPU
The number of players online
The Metrics version

You can disable it by changing "opt-out" to "true" in the config.

CommandBlock+