Current in db/services.php, the external function developer can list the capabilities he/she used when implementing the function. This list is displayed to the administrator. Missing capabilities are displayed for authorised users and also for manually created tokens.

It would be good instead to display a mix of mandatory/conditional capabilities to:
Make the list of capabilities a list of array:

• capability name
• context
• manadatory / conditional
• description: mainly to explain when the capability is conditional, what are the condition.

Without these information, it's a bit a hit and miss game that the administrator needs to play with the functions.