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

* AI generated `///` comment updates

* Fix compilation issues

* Fix incorrect XML comment structure

* Update all Client comments

* Update all Configuration comments

* Update all Messages comments

* Update all Transport comments

* Update all Types comments

* Update all Server comments

* Undo some commenting

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

src/ModelContextProtocol/Protocol/Types/RequestParams.cs

@@ -3,14 +3,20 @@ using System.Text.Json.Serialization;
 namespace ModelContextProtocol.Protocol.Types;
 
 /// <summary>
-/// Base class for all request parameters.
-/// <see href="https://github.com/modelcontextprotocol/specification/blob/main/schema/#L771-L806">See the schema for details</see>
+/// Provides a base class for all request parameters.
 /// </summary>
+/// <remarks>
+/// See the <see href="https://github.com/modelcontextprotocol/specification/blob/main/schema/">schema</see> for details.
+/// </remarks>
 public abstract class RequestParams
 {
     /// <summary>
-    /// Metadata related to the tool invocation.
+    /// Gets or sets metadata related to the request that provides additional protocol-level information.
     /// </summary>
+    /// <remarks>
+    /// This can include progress tracking tokens and other protocol-specific properties
+    /// that are not part of the primary request parameters.
+    /// </remarks>
     [JsonPropertyName("_meta")]
     public RequestParamsMetadata? Meta { get; init; }
 }