docs: update Root and RootsCapability XML doc comments to clarify informational nature

Agent-Logs-Url: https://github.com/modelcontextprotocol/csharp-sdk/sessions/d5710a76-b57b-4d4c-ba62-c73c7d50f862

Co-authored-by: stephentoub <2642209+stephentoub@users.noreply.github.com>

Author: Copilot

src/ModelContextProtocol.Core/Protocol/Root.cs

@@ -9,9 +9,10 @@ namespace ModelContextProtocol.Protocol;
 /// </summary>
 /// <remarks>
 /// Root URIs serve as entry points for resource navigation, typically representing
-/// top-level directories or container resources that can be accessed and traversed.
-/// Roots provide a hierarchical structure for organizing and accessing resources within the protocol.
-/// Each root has a URI that uniquely identifies it and optional metadata like a human-readable name.
+/// top-level directories or container resources that are relevant to the current session.
+/// Roots inform servers which locations the client considers important, providing informational
+/// guidance rather than an access-control mechanism. Each root has a URI that uniquely identifies
+/// it and optional metadata like a human-readable name.
 /// </remarks>
 public sealed class Root
 {

src/ModelContextProtocol.Core/Protocol/RootsCapability.cs

@@ -13,9 +13,9 @@ namespace ModelContextProtocol.Protocol;
 /// root URIs that serve as entry points for resource navigation.
 /// </para>
 /// <para>
-/// The roots capability establishes a mechanism for servers to discover and access the hierarchical
-/// structure of resources provided by a client. Root URIs represent top-level entry points from which
-/// servers can navigate to access specific resources.
+/// The roots capability establishes a mechanism for servers to discover the directories and files
+/// the client considers relevant. Root URIs represent top-level entry points that inform the server
+/// about the working context, providing informational guidance rather than enforcing access control.
 /// </para>
 /// <para>
 /// See the <see href="https://github.com/modelcontextprotocol/specification/blob/main/schema/">schema</see> for details.