Update the migration guidelines with latest changes

Author: rogerbarreto

.github/upgrades/prompts/SemanticKernelToAgentFramework.md

@@ -142,9 +142,9 @@ Replace these Semantic Kernel agent classes with their Agent Framework equivalen
 |----------------------|----------------------------|-------------------|
 | `IChatCompletionService` | `IChatClient` | Convert to `IChatClient` using `chatService.AsChatClient()` extensions |
 | `ChatCompletionAgent` | `ChatClientAgent` | Remove `Kernel` parameter, add `IChatClient` parameter |
-| `OpenAIAssistantAgent` | `AIAgent` (via extension) | **New**: `OpenAIClient.GetAssistantClient().CreateAIAgent()` <br> **Existing**: `OpenAIClient.GetAssistantClient().GetAIAgent(assistantId)` |
+| `OpenAIAssistantAgent` | `AIAgent` (via extension) | ⚠️ **Deprecated** - Use Responses API instead. <br> **New**: `OpenAIClient.GetAssistantClient().CreateAIAgent()` <br> **Existing**: `OpenAIClient.GetAssistantClient().GetAIAgent(assistantId)` |
 | `AzureAIAgent` | `AIAgent` (via extension) | **New**: `PersistentAgentsClient.CreateAIAgent()` <br> **Existing**: `PersistentAgentsClient.GetAIAgent(agentId)` |
-| `OpenAIResponseAgent` | `AIAgent` (via extension) | Replace with `OpenAIClient.GetOpenAIResponseClient().CreateAIAgent()` |
+| `OpenAIResponseAgent` | `AIAgent` (via extension) | Replace with `OpenAIClient.GetOpenAIResponseClient(modelId).CreateAIAgent()` |
 | `A2AAgent` | `AIAgent` (via extension) | Replace with `A2ACardResolver.GetAIAgentAsync()` |
 | `BedrockAgent` | Not supported | Custom implementation required |
 
@@ -529,14 +529,14 @@ AIAgent agent = new OpenAIClient(apiKey)
     .CreateAIAgent(instructions: instructions);
 ```
 
-**OpenAI Assistants (New):**
+**OpenAI Assistants (New):** ⚠️ *Deprecated - Use Responses API instead*
 ```csharp
 AIAgent agent = new OpenAIClient(apiKey)
     .GetAssistantClient()
     .CreateAIAgent(modelId, instructions: instructions);
 ```
 
-**OpenAI Assistants (Existing):**
+**OpenAI Assistants (Existing):** ⚠️ *Deprecated - Use Responses API instead*
 ```csharp
 AIAgent agent = new OpenAIClient(apiKey)
     .GetAssistantClient()
@@ -562,6 +562,20 @@ AIAgent agent = await new PersistentAgentsClient(endpoint, credential)
     .GetAIAgentAsync(agentId);
 ```
 
+**OpenAI Responses:** *(Recommended for OpenAI)*
+```csharp
+AIAgent agent = new OpenAIClient(apiKey)
+    .GetOpenAIResponseClient(modelId)
+    .CreateAIAgent(instructions: instructions);
+```
+
+**Azure OpenAI Responses:** *(Recommended for Azure OpenAI)*
+```csharp
+AIAgent agent = new AzureOpenAIClient(endpoint, credential)
+    .GetOpenAIResponseClient(deploymentName)
+    .CreateAIAgent(instructions: instructions);
+```
+
 **A2A:**
 ```csharp
 A2ACardResolver resolver = new(new Uri(agentHost));
@@ -980,6 +994,8 @@ AIAgent agent = new AzureOpenAIClient(new Uri(endpoint), new AzureCliCredential(
 
 ### 3. OpenAI Assistants Migration
 
+> ⚠️ **DEPRECATION WARNING**: The OpenAI Assistants API has been deprecated. The Agent Framework extension methods for Assistants are marked as `[Obsolete]`. **Please use the Responses API instead** (see Section 6: OpenAI Responses Migration).
+
 <configuration_changes>
 **Remove Semantic Kernel Packages:**
 ```xml
@@ -1291,52 +1307,7 @@ var result = await agent.RunAsync(userInput, thread);
 ```
 </api_changes>
 
-### 8. A2A Migration
-
-<configuration_changes>
-**Remove Semantic Kernel Packages:**
-```xml
-<PackageReference Include="Microsoft.SemanticKernel.Agents.A2A" />
-```
-
-**Add Agent Framework Packages:**
-```xml
-<PackageReference Include="Microsoft.Agents.AI.A2A" />
-```
-</configuration_changes>
-
-<api_changes>
-**Replace this Semantic Kernel pattern:**
-```csharp
-using A2A;
-using Microsoft.SemanticKernel;
-using Microsoft.SemanticKernel.Agents;
-using Microsoft.SemanticKernel.Agents.A2A;
-
-using var httpClient = CreateHttpClient();
-var client = new A2AClient(agentUrl, httpClient);
-var cardResolver = new A2ACardResolver(url, httpClient);
-var agentCard = await cardResolver.GetAgentCardAsync();
-Console.WriteLine(JsonSerializer.Serialize(agentCard, s_jsonSerializerOptions));
-var agent = new A2AAgent(client, agentCard);
-```
-
-**With this Agent Framework pattern:**
-```csharp
-using System;
-using A2A;
-using Microsoft.Agents.AI;
-using Microsoft.Agents.AI.A2A;
-
-// Initialize an A2ACardResolver to get an A2A agent card.
-A2ACardResolver agentCardResolver = new(new Uri(a2aAgentHost));
-
-// Create an instance of the AIAgent for an existing A2A agent specified by the agent card.
-AIAgent agent = await agentCardResolver.GetAIAgentAsync();
-```
-</api_changes>
-
-### 9. Unsupported Providers (Require Custom Implementation)
+### 8. Unsupported Providers (Require Custom Implementation)
 
 <behavioral_changes>
 #### BedrockAgent Migration
@@ -1507,7 +1478,7 @@ Console.WriteLine(result);
 ```
 </behavioral_changes>
 
-### 10. Function Invocation Filtering
+### 9. Function Invocation Filtering
 
 **Invocation Context**
 
@@ -1615,25 +1586,4 @@ var filteredAgent = originalAgent
     .Build();
 ```
 
-### 11. Function Invocation Contexts
-
-**Invocation Context**
-
-Semantic Kernel's `IAutoFunctionInvocationFilter` provides a `AutoFunctionInvocationContext` where Agent Framework provides `FunctionInvocationContext` 
 
-The property mapping guide from a `AutoFunctionInvocationContext` to a `FunctionInvocationContext` is as follows:
-
-| Semantic Kernel | Agent Framework |
-| --- | --- |
-| RequestSequenceIndex | Iteration |
-| FunctionSequenceIndex | FunctionCallIndex |
-| ToolCallId | CallContent.CallId |
-| ChatMessageContent | Messages[0] |
-| ExecutionSettings | Options |
-| ChatHistory | Messages |
-| Function | Function |
-| Kernel | N/A |
-| Result | Use `return` from the delegate |
-| Terminate | Terminate |
-| CancellationToken | provided via argument to middleware delegate |
-| Arguments | Arguments |