I'm using facebook sdk to share details to facebook and it works fine. Now my question, is there a way to set description to "What's on your mind?" text field.

I'm using facebook sdk to share details to facebook and it works fine. Now my question, is there a way to set description to "What's on your mind?" text field.

Feed Dialogs (deprecated) used to have a message parameter earlier, but facebook removed. Also, there's no way to pre-populate the message in the Share Dialog.
They have removed this purposely in the UI Dialogs. If you are posting a feed using the API (not dialog), then only you can populate the message with message parameter.
The abcd text is the description of the link that you (or the link admin) have provided; but the message is related to user and in case of dialogs, facebook expects that the user himself should give any message if he wants to, it should not be app-written.