I wouldn’t have that mismatch, but I understand it.
I expect markdown to do exactly what I’m saying: [link] means render the following as a link; it’s up to me to put a valid URL in there.
I expect the composer to do a bit of magic: this looks like it’s meant to be a URL so I’ll mark it up as a link.
This has become natural to me, but I certainly see potential for confusion. Maybe similar magic could be applied to validate the format of markdown links before linkifying them.