Clean up markdown-link-check workflow and fix stale URLs

- Remove stale ignore rules for anthropic.com and hackerone.com
- Add ignore rule for DocFX xref: links that mlc cannot check
- Add redirect suppression for learn.microsoft.com locale redirects
- Remove stale redirect rules for modelcontextprotocol.io and GitHub login
- Update RFC URLs from tools.ietf.org to datatracker.ietf.org
- Update GitHub Pages URLs to csharp.sdk.modelcontextprotocol.io custom domain
- Reformat args to multi-line with descriptive comments

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

Author: jeffhandley

.github/workflows/markdown-link-check.yml

@@ -21,5 +21,13 @@ jobs:
       - name: Markup Link Checker (mlc)
         uses: becheran/mlc@7ec24825cefe0c9c8c6bac48430e1f69e3ec356e # v1.2.0
         with:
-          # Ignore external links that result in 403 errors during CI. Do not warn for redirects where we want to keep the vanity URL in the markdown or for GitHub links that redirect to the login, and DocFX snippet links.
-          args: --ignore-links "https://www.anthropic.com/*,https://hackerone.com/anthropic-vdp/*" --do-not-warn-for-redirect-to "https://modelcontextprotocol.io/*,https://github.com/login?*" --ignore-links "*samples/*?name=snippet_*" ./docs
+          # Ignore DocFX cross-reference links (xref:) that mlc cannot check.
+          # Ignore DocFX snippet inclusion links.
+          # Do not warn for learn.microsoft.com locale redirects.
+          # Do not warn for modelcontextprotocol.io homepage/spec redirects.
+          args: >-
+            --ignore-links "xref:*"
+            --ignore-links "*samples/*?name=snippet_*"
+            --do-not-warn-for-redirect-to "https://learn.microsoft.com/en-us/*"
+            --do-not-warn-for-redirect-to "https://modelcontextprotocol.io/*"
+            ./docs

docs/concepts/logging/logging.md

@@ -15,7 +15,7 @@ This document describes how to implement logging in MCP servers and how clients
 
 ### Logging Levels
 
-MCP uses the logging levels defined in [RFC 5424](https://tools.ietf.org/html/rfc5424).
+MCP uses the logging levels defined in [RFC 5424](https://datatracker.ietf.org/doc/html/rfc5424).
 
 The MCP C# SDK uses the standard .NET [ILogger] and [ILoggerProvider] abstractions, which support a slightly
 different set of logging levels. The following table shows the levels and how they map to standard .NET logging levels.

docs/concepts/resources/resources.md

@@ -43,7 +43,7 @@ public class MyResources
 
 Template resources use [URI templates (RFC 6570)] with parameters. They are returned separately in the resource templates list and can match a range of URIs:
 
-[URI templates (RFC 6570)]: https://tools.ietf.org/html/rfc6570
+[URI templates (RFC 6570)]: https://datatracker.ietf.org/doc/html/rfc6570
 
 ```csharp
 [McpServerResourceType]

docs/index.md

@@ -8,8 +8,8 @@ This SDK is the official C# SDK for the [Model Context Protocol](https://modelco
 
 For more details on available functionality, see:
 
-- [Conceptual documentation](https://modelcontextprotocol.github.io/csharp-sdk/concepts/index.html)
-- [API documentation](https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.html).
+- [Conceptual documentation](https://csharp.sdk.modelcontextprotocol.io/concepts/index.html)
+- [API documentation](https://csharp.sdk.modelcontextprotocol.io/api/ModelContextProtocol.html).
 
 ## About MCP
 

docs/list-of-diagnostics.md

@@ -9,7 +9,7 @@ Analyzer diagnostic IDs are in the format `MCP###`.
 | Diagnostic ID | Description |
 | :------------ | :---------- |
 | `MCP001` | Invalid XML documentation for MCP method |
-| `MCP002` | MCP method must be partial to generate [Description] attributes |
+| `MCP002` | MCP method must be partial to generate `[Description]` attributes |
 
 ## Experimental APIs
 

docs/roadmap.md

@@ -6,7 +6,7 @@ uid: roadmap
 ---
 ## Spec Implementation Tracking
 
-The C# SDK tracks implementation of MCP spec components using the [modelcontextprotocol project boards](https://github.com/orgs/modelcontextprotocol/projects), with a dedicated project board for each spec revision. For example, see the [2025-11-25 spec revision board](https://github.com/orgs/modelcontextprotocol/projects/26).
+The C# SDK tracks implementation of MCP spec components using the [modelcontextprotocol project boards](https://github.com/orgs/modelcontextprotocol/projects?query=is%3Aopen), with a dedicated project board for each spec revision. For example, see the [2025-11-25 spec revision board](https://github.com/orgs/modelcontextprotocol/projects/26).
 
 ## Current Focus Areas
 

docs/versioning.md

@@ -43,7 +43,7 @@ All releases are posted to https://github.com/modelcontextprotocol/csharp-sdk/re
 
 ### Specification schema changes
 
-If the MCP specification changes the schema for JSON payloads, the C# SDK might use the [`McpSession.NegotiatedProtocolVersion`](https://modelcontextprotocol.github.io/csharp-sdk/api/ModelContextProtocol.McpSession.html#ModelContextProtocol_McpSession_NegotiatedProtocolVersion) to dynamically change the payload schema, potentially using internal data transfer objects (DTOs) to achieve the needed deserialization behavior. These techniques will be applied where feasible to maintain backward-compatibility and forward-compatibility between MCP specification versions.
+If the MCP specification changes the schema for JSON payloads, the C# SDK might use the [`McpSession.NegotiatedProtocolVersion`](https://csharp.sdk.modelcontextprotocol.io/api/ModelContextProtocol.McpSession.html#ModelContextProtocol_McpSession_NegotiatedProtocolVersion) to dynamically change the payload schema, potentially using internal data transfer objects (DTOs) to achieve the needed deserialization behavior. These techniques will be applied where feasible to maintain backward-compatibility and forward-compatibility between MCP specification versions.
 
 For illustrations of how this could be achieved, see the following prototypes: