AI seeded comments from robch and then edited by stephentoub (#238)

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Co-authored-by: Stephen Toub <stoub@microsoft.com>

src/ModelContextProtocol/Utils/SemaphoreSlimExtensions.cs

@@ -1,15 +1,40 @@
-namespace ModelContextProtocol.Utils;
+namespace ModelContextProtocol.Utils;
 
 internal static class SynchronizationExtensions
 {
+    /// <summary>
+    /// Asynchronously acquires a lock on the semaphore and returns a disposable object that releases the lock when disposed.
+    /// </summary>
+    /// <param name="semaphore">The semaphore to acquire a lock on.</param>
+    /// <param name="cancellationToken">A cancellation token to observe while waiting for the semaphore.</param>
+    /// <returns>A disposable <see cref="Releaser"/> that releases the semaphore when disposed.</returns>
+    /// <remarks>
+    /// This extension method provides a convenient pattern for using a semaphore in asynchronous code,
+    /// similar to how the `lock` statement is used in synchronous code.
+    /// </remarks>
+    /// <exception cref="OperationCanceledException">The <paramref name="cancellationToken"/> was canceled.</exception>
     public static async ValueTask<Releaser> LockAsync(this SemaphoreSlim semaphore, CancellationToken cancellationToken = default)
     {
         await semaphore.WaitAsync(cancellationToken).ConfigureAwait(false);
         return new(semaphore);
     }
 
+    /// <summary>
+    /// A disposable struct that releases a semaphore when disposed.
+    /// </summary>
+    /// <remarks>
+    /// This struct is used with the <see cref="LockAsync"/> extension method to provide
+    /// a using-pattern for semaphore locking, similar to lock statements.
+    /// </remarks>
     public readonly struct Releaser(SemaphoreSlim semaphore) : IDisposable
     {
+        /// <summary>
+        /// Releases the semaphore.
+        /// </summary>
+        /// <remarks>
+        /// This method is called automatically when the <see cref="Releaser"/> goes out of scope
+        /// in a using statement or expression.
+        /// </remarks>
         public void Dispose() => semaphore.Release();
     }
 }