Could I make additional text show up in the WordPress editor?

I'm creating a library which wraps a couple of existing libraries. I would like to add extra text to the editor to guide content authors when creating content. When I give authors a choice of two libraries they will see the associated label text from the semantics.json in the WordPress editor. i.e. when my semantics file contains the following, the label's text is displayed.

{"name": "preTaskChoice","type": "library","label": "First, you need to demonstrate the activity so people get a sense of what it's all about. Choose which H5P type you would like to use to create your demonstration","options": ["H5P.InteractiveVideo 1.21", "H5P.ThreeImage 0.3"]}

 

However, when I take the same approach but only set one option the label does not display in the editor. 

{"name": "mainTaskChoice","type": "library","label": "Next, you should demonstrate the process of undertaking the activity. Show what resources are used and what stages you go through.","options": ["H5P.InteractiveVideo 1.21"]}

 

I would like some way to display this label's text in the editor. Any ideas how I could achieve this? 

Thanks,

Colin