Direct recall questions are open response-style, and ask you to exercise free recall, or to remember the answer without any prompting. Firecracker includes over 30,000 published recall-style questions for the Firecracker MD program, and even more in Firecracker DO. These questions are designed to help you build up your knowledge-base. You can access these kinds of questions in your Review and/or Refresh tasks, as well as via the blue "Do Review Questions" buttons.
The recall scoring system asks you to assign a rating between 1 and 5 (Likert scale) for your knowledge before looking at the answer to each question. Try to answer the questions in your head prior to peeking at their answers. Once you've answered the question in your head, hit the "Show Answer" button to reveal the answer. Then score your ability to recall the answer honestly, according to how well you were able to answer that question before you had looked at the answer.
Scoring a 1 means you didn't know the answer well at all. Scoring a 2 means you only knew a part of the answer, but were unfamiliar with the majority of the answer. Scoring a 3 means you had to think hard about that question, or only knew about half of the answer. Scoring a 4 means you had little to no trouble with that question. Scoring a 5 means you could answer that question in your sleep.
You can always expand out additional context by hitting the blue "More details..." and/or "Show related topic details" links, but you should not expect yourself to memorize the full topic summaries. Rate your recall (1-5) according to how well you knew that specific answer to that specific question only. Your recall ratings (1-5) will factor into Firecracker's spaced repetition recommendations, so you'll see the most frequent recommended reviews of the questions you rate 1 and 2.