Commands could be configured following a structure

[Alon-L]

e.x.

{
  name: 'help',
  aliases: ['h', 'help!'],
  permissions: ['SEND_MESSAGES'],
}

If the bot lacks a permission, an InvalidPermission error will be threw. Users will be able to catch these errors and check:

try {
...
} catch(err) {
  if (err instanceof InvalidPermission) {
     ...
  }
}