Making an Evernote note is great with do. I don't have to launch the app and risk switching context. Same with Todoist, Salesforce chatter, and more. The idea of one way UX (not just react-style unidirectional dataflow) where the user has a view for just data entry or retrieval is a powerful one.
I use it to email notes to myself. This recipe is one of the top killer features of my Apple Watch, as it means I always have a GTD input device available within about ten seconds.
The Maker Channel Action doesn't support authenticated requests, at least anything beyond something you could send in the URL or body of the message. We do this to prevent people from using it to spoof requests to public authenticated services that might view such behavior as slightly "shady". The Maker Channel is really meant for prototyping and experimenting and so we've limited the capabilities to keep the uses in that realm. Hope that helps!
That's somewhat of a bummer, as it also forces all legitimate users to leave their endpoints acessible for everyone who knows the URL.
Have you thought about at least adding support for authentication where the credentials are generated by IFTTT? (Similar to the "secret" that you use for the trigger) This would allow makers to protect their endpoints while still disallowing spoofed requests.
