Fix XML doc comment issues in Protocol types

- BlobResourceContents.cs: Fix 'an' to 'a' before 'BlobResourceContents' (consonant sound)
- BlobResourceContents.cs: Remove empty <exception> tag on FromBytes (method doesn't throw)
- CompletionsCapability.cs: Fix 'sampling capabilities' to 'completions capabilities' (copy-paste error)
- ContentBlock.cs: Wrap dangling comment in <remarks> tag and fix double space

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

Author: Copilot

src/ModelContextProtocol.Core/Protocol/BlobResourceContents.cs

@@ -32,13 +32,12 @@ public sealed class BlobResourceContents : ResourceContents
     private ReadOnlyMemory<byte>? _blob;
 
     /// <summary>
-    /// Creates an <see cref="BlobResourceContents"/> from raw data.
+    /// Creates a <see cref="BlobResourceContents"/> from raw data.
     /// </summary>
     /// <param name="bytes">The raw unencoded data.</param>
     /// <param name="uri">The URI of the blob resource.</param>
     /// <param name="mimeType">The optional MIME type of the data.</param>
     /// <returns>A new <see cref="BlobResourceContents"/> instance.</returns>
-    /// <exception cref="InvalidOperationException"></exception>
     public static BlobResourceContents FromBytes(ReadOnlyMemory<byte> bytes, string uri, string? mimeType = null)
     {
         return new(bytes, uri, mimeType);

src/ModelContextProtocol.Core/Protocol/CompletionsCapability.cs

@@ -22,7 +22,7 @@ namespace ModelContextProtocol.Protocol;
 /// </para>
 /// <para>
 /// This class is intentionally empty as the Model Context Protocol specification does not
-/// currently define additional properties for sampling capabilities. Future versions of the
+/// currently define additional properties for completions capabilities. Future versions of the
 /// specification might extend this capability with additional configuration options.
 /// </para>
 /// </remarks>

src/ModelContextProtocol.Core/Protocol/ContentBlock.cs

@@ -69,8 +69,10 @@ private protected ContentBlock()
     /// <summary>
     /// Provides a <see cref="JsonConverter"/> for <see cref="ContentBlock"/>.
     /// </summary>
-    /// Provides a polymorphic converter for the <see cref="ContentBlock"/> class that doesn't  require
+    /// <remarks>
+    /// Provides a polymorphic converter for the <see cref="ContentBlock"/> class that doesn't require
     /// setting <see cref="JsonSerializerOptions.AllowOutOfOrderMetadataProperties"/> explicitly.
+    /// </remarks>
     [EditorBrowsable(EditorBrowsableState.Never)]
     public sealed class Converter : JsonConverter<ContentBlock>
     {