Revise AI highlight example (#48880)

* Revise AI highlight example

* Fix build warning

* Updates per feedback

* Updates per Mike's feedback

Removed redundant text about using AI tools for migration and streamlined the example prompt section.

Author: anandmeg

docs/standard/serialization/system-text-json/migrate-from-newtonsoft.md

@@ -2,7 +2,7 @@
 title: "Migrate from Newtonsoft.Json to System.Text.Json - .NET"
 description: "Learn about the differences between Newtonsoft.Json and System.Text.Json and how to migrate to System.Text.Json."
 no-loc: [System.Text.Json, Newtonsoft.Json]
-ms.date: 02/11/2025
+ms.date: 10/03/2025
 helpviewer_keywords:
   - "JSON serialization"
   - "serializing objects"
@@ -24,7 +24,7 @@ The `System.Text.Json` namespace provides functionality for serializing to and d
 * .NET Core 2.0, 2.1, and 2.2
 
 > [!TIP]
-> You can use AI assistance to [migrate from `Newtonsoft.Json`](#use-ai-to-migrate).
+> You can use AI assistance to [migrate from `Newtonsoft.Json`](#use-ai-for-solution-wide-migration).
 
 `System.Text.Json` focuses primarily on performance, security, and standards compliance. It has some key differences in default behavior and doesn't aim to have feature parity with `Newtonsoft.Json`. For some scenarios, `System.Text.Json` currently has no built-in functionality, but there are recommended workarounds. For other scenarios, workarounds are impractical.
 
@@ -639,26 +639,22 @@ System.Text.Json sets limits that can't be changed for some values, such as the
 
 Newtonsoft parses `NaN`, `Infinity`, and `-Infinity` JSON string tokens. With System.Text.Json, use <xref:System.Text.Json.Serialization.JsonNumberHandling.AllowNamedFloatingPointLiterals?displayProperty=nameWithType>. For information about how to use this setting, see [Allow or write numbers in quotes](invalid-json.md#allow-or-write-numbers-in-quotes).
 
-## Use AI to migrate
+## Use AI for solution-wide migration
 
-You can use AI tools, such as GitHub Copilot, to migrate your code from `Newtonsoft.Json` to `System.Text.Json` within your IDE. You can customize the prompt per your requirements.
+You can use AI tools, such as GitHub Copilot, to help with migrating your solution code from `Newtonsoft.Json` to `System.Text.Json`.
 
-**Example prompt for Copilot Chat**
+Here's an example prompt you can use in Visual Studio Copilot Chat to migrate a solution.
 
 ```copilot-prompt
-convert the following code to use System.Text.Json
-Product product = new Product();
-
-product.Name = "Apple";
-product.ExpiryDate = new DateTime(2024, 08, 08);
-product.Price = 3.99M;
-product.Sizes = new string[] { "Small", "Medium", "Large" };
-
-string output = JsonConvert.SerializeObject(product);
-Console.WriteLine(output);
+Convert all serialization code in this #solution from Newtonsoft.Json to System.Text.Json, using the recommended approach for my current .NET version.
+- Update attributes and properties, including rules for skipping or renaming during serialization 
+- Ensure polymorphic serialization continues to work correctly
+- Respect existing custom converters and project-level settings (for example, from the Utilities folder or appsettings.json)
+- Update related unit tests and highlight any potential breaking changes
+- Generate a migration summary
 ```
 
-GitHub Copilot is powered by AI, so surprises and mistakes are possible. For more information, see [Copilot FAQs](https://aka.ms/copilot-general-use-faqs).
+Review Copilot's suggestions before applying. For more information, see [Copilot FAQs](https://aka.ms/copilot-general-use-faqs).
 
 ## Additional resources