When posting to Facebook, our tool needs to be in line with all Facebook policies. Especially when it comes to prefilling messages, Facebook has its own guidelines on how content can look.
The idea behind Facebook Policy is that when it comes to publishing, users should have full control over the content going out. In other words, applications like ours should not prefill the message - all content should be created and published by a user. Facebook has made a nice, short tutorial on this topic, here.
So, for example, when using our Chrome extension for publishing, please, customize the message that you send out since we are not allowed to prefill it for you.