Code Smarter with Cursor/

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AI-Driven Code Explanation and Documentation

AI-Driven Code Explanation and Documentation

Learn how to use Cursor to understand unfamiliar code and generate useful documentation with minimal effort.

We'll cover the following...

In this lesson, we’ll explore how Cursor can help us understand and document code. Whether we’re reviewing someone else’s work, returning to an old project, or trying to get up to speed quickly, Cursor’s AI features can save time and reduce confusion.

We’ll learn how to:

  • Use Cursor to explain the selected code in plain language.

  • Understand complex logic by asking focused questions.

  • Generate comments and docstrings using the assistant.

  • Produce project-level documentation and summaries with minimal manual effort.

Instead of writing everything from scratch, we’ll focus on how Cursor can assist us in understanding what code does and how to document it clearly for ourselves and others.

Starting with a code snippet that needs explanation

Let’s say we come across the following piece of code in a project we didn’t write ourselves. Before making any changes, we want to understand what it does.

class RateLimiter:
    def __init__(self, max_calls, window_seconds):
        self.max_calls = max_calls
        self.window_seconds = window_seconds
        self.call_times = []
    def allow_request(self, current_time):
        self.call_times = [t for t in self.call_times if current_time - t < self.window_seconds]
        if len(self.call_times) < self.max_calls:
            self.call_times.append(current_time)
            return True
        return False

There are no comments or docstrings. The method names give us a hint, but the actual logic needs a closer look. Instead of reading through it line by line and trying to piece it together manually, we’ll use Cursor to help explain what this class does and how each part works.

Using Cursor to understand unfamiliar code

We start by selecting the allow_request method and opening the Cursor chat. Since there’s no existing documentation or comments, we ask:

Prompt: Can you ...