To give custom parameters to facebook share its better to give only the link and facebook gets its Title + Description + Picture automatically from the page that you are sharing.
In order to "help" facebook API find those things you can put the following things in the header of the page that you are sharing:
You can customize Facebook share dialog box by using asynchronous JavaScript SDK provided by Facebook and setting up its parameter values
Have a look at the following code:
<script type="text/javascript">
$(document).ready(function(){
$('#share_button').click(function(e){
e.preventDefault();
FB.ui(
{
method: 'feed',
name: 'This is the content of the "name" field.',
link: 'URL which you would like to share ',
picture: ‘URL of the image which is going to appear as thumbnail image in share dialogbox’,
caption: 'Caption like which appear as title of the dialog box',
description: 'Small description of the post',
message: ''
}
);
});
});
</script>
Before copying and pasting the below code you must first initialize the SDK and set up jQuery library. Please click here to know a step by step how to set information on the same.