The Open Graph object callback is truncated. Is there a character limitation?

I am posting actions to a user's timeline by submitting to graph.facebook.com as described in a tutorial in the Facebook documentation.

 FB.api(
        '/me/[YOUR_APP_NAMESPACE]:cook?recipe=http://fbwerks.com:8000/zhen/cookie.html',
        'post',
        function(response) {
           if (!response || response.error) {
              alert('Error occured');
           } else {
              alert('Cook was successful! Action ID: ' + response.id);
           }
        });

      

        
        
        
      

    

However, when Facebook calls my object url, I am not getting all the GET parameters I went through and it looks like Facebook is truncating the url. Is there a limit on the size of the object url? The url works fine when I put it in the object debugger.