Is there some special reason you are using a KM Named Clipboard?
If the data you want is plain text, then it is almost always better to save it to a KM Variable. If you save it as a Global Variable then it will be available to all macros, and even across Mac restarts (just like files).
So, instead of this:
use this:
That should set the KM Variable "Agenda_URL" to the URL:
agenda://note/D1BC0274-50D9-45B4-9222-D5EE79D42782
You will need to adjust your Macro to use this KM Variable, rather than the Named Clipboard.
BTW, just to be clear on terms, what you want is the "URL", not the "UUID".
What you are seeing on the clipboard is usually referred to as a "hyperlink", like this:
Agenda - Date-focused Note Taking
Questions?