If an AI variable provider chooses to provide a completion items rather than triggering an argument picker to let the user specify the arguments, the variable provider needs to awkwardly implement triggerArgumentPicker() calling this.commandService.executeCommand('editor.action.triggerSuggest');. See

We should make this a viable option and avoid this awkward workaround.

@planger I used the variable argument picker to trigger the argument autocompletion. However, I only trigger your suggested command there and do not actually pick an argument myself. Please have a brief look whether this solution is okay for you. Using the command property of a completion does not work that easily here because the base variable names are provided by the default completion provider that already registers said argument picker command.

Originally posted by @lucas-koehler in #15196 (comment)