.Net: Add date to obsolete messages for when to expect these methods to be deleted. (#11329)

### Motivation and Context

We should warm users of the timeframe at which obsoleted methods will be
deleted.
#11315 

### Description

Add a date to the obsolete messages for obsolete methods on the agent
implementations.

### Contribution Checklist

<!-- Before submitting this PR, please make sure: -->

- [ ] The code builds clean without any errors or warnings
- [ ] The PR follows the [SK Contribution
Guidelines](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md)
and the [pre-submission formatting
script](https://github.com/microsoft/semantic-kernel/blob/main/CONTRIBUTING.md#development-scripts)
raises no violations
- [ ] All unit tests pass, and I have added new tests where possible
- [ ] I didn't break anyone 😄

Author: westey-m

dotnet/src/Agents/AzureAI/AzureAIAgent.cs

@@ -106,7 +106,7 @@ public AzureAIAgent(
     /// <remarks>
     /// Only supports messages with <see href="https://platform.openai.com/docs/api-reference/runs/createRun#runs-createrun-additional_messages">role = User or agent</see>.
     /// </remarks>
-    [Obsolete("Pass messages directly to Invoke instead.")]
+    [Obsolete("Pass messages directly to Invoke instead. This method will be removed after May 1st 2025.")]
     public Task AddChatMessageAsync(string threadId, ChatMessageContent message, CancellationToken cancellationToken = default)
     {
         return AgentThreadActions.CreateMessageAsync(this.Client, threadId, message, cancellationToken);
@@ -118,7 +118,7 @@ public Task AddChatMessageAsync(string threadId, ChatMessageContent message, Can
     /// <param name="threadId">The thread identifier.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An asynchronous enumeration of messages.</returns>
-    [Obsolete("Use the AzureAIAgentThread to retrieve messages instead.")]
+    [Obsolete("Use the AzureAIAgentThread to retrieve messages instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> GetThreadMessagesAsync(string threadId, CancellationToken cancellationToken = default)
     {
         return AgentThreadActions.GetMessagesAsync(this.Client, threadId, null, cancellationToken);
@@ -135,7 +135,7 @@ public IAsyncEnumerable<ChatMessageContent> GetThreadMessagesAsync(string thread
     /// <remarks>
     /// The `arguments` parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         string threadId,
         KernelArguments? arguments = null,
@@ -236,7 +236,7 @@ async IAsyncEnumerable<ChatMessageContent> InternalInvokeAsync()
     /// <remarks>
     /// The `arguments` parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         string threadId,
         AzureAIInvocationOptions? options,
@@ -345,7 +345,7 @@ public async IAsyncEnumerable<AgentResponseItem<StreamingChatMessageContent>> In
     /// <remarks>
     /// The `arguments` parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         string threadId,
         KernelArguments? arguments = null,
@@ -369,7 +369,7 @@ public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
     /// <remarks>
     /// The `arguments` parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         string threadId,
         AzureAIInvocationOptions? options,

dotnet/src/Agents/Bedrock/BedrockAgent.cs

@@ -215,7 +215,7 @@ public async IAsyncEnumerable<AgentResponseItem<ChatMessageContent>> InvokeAsync
     /// <param name="invokeAgentRequest">The request to send to the agent.</param>
     /// <param name="arguments">The arguments to use when invoking the agent.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         InvokeAgentRequest invokeAgentRequest,
         KernelArguments? arguments,
@@ -281,7 +281,7 @@ async IAsyncEnumerable<ChatMessageContent> InvokeInternal()
     /// <param name="agentAliasId">The alias id of the agent to use. The default is the working draft alias id.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="IAsyncEnumerable{T}"/> of <see cref="ChatMessageContent"/>.</returns>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         string sessionId,
         string message,
@@ -456,7 +456,7 @@ public async IAsyncEnumerable<AgentResponseItem<StreamingChatMessageContent>> In
     /// <param name="agentAliasId">The alias id of the agent to use. The default is the working draft alias id.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="IAsyncEnumerable{T}"/> of <see cref="ChatMessageContent"/>.</returns>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         string sessionId,
         string message,
@@ -486,7 +486,7 @@ public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
     /// <param name="arguments">The arguments to use when invoking the agent.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="IAsyncEnumerable{T}"/> of <see cref="StreamingChatMessageContent"/>.</returns>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         InvokeAgentRequest invokeAgentRequest,
         KernelArguments? arguments,

dotnet/src/Agents/Core/ChatCompletionAgent.cs

@@ -127,7 +127,7 @@ public override async IAsyncEnumerable<AgentResponseItem<ChatMessageContent>> In
     }
 
     /// <inheritdoc/>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public override IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         ChatHistory history,
         KernelArguments? arguments = null,
@@ -187,7 +187,7 @@ public override async IAsyncEnumerable<AgentResponseItem<StreamingChatMessageCon
     }
 
     /// <inheritdoc/>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public override IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         ChatHistory history,
         KernelArguments? arguments = null,

dotnet/src/Agents/OpenAI/OpenAIAssistantAgent.cs

@@ -89,7 +89,7 @@ public OpenAIAssistantAgent(
     /// An assistant removed by other means will result in an exception when invoked.
     /// </remarks>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAI.Assistants.AssistantClient to manage the Assistant definition lifecycle.")]
+    [Obsolete("Use the OpenAI.Assistants.AssistantClient to manage the Assistant definition lifecycle. This method will be removed after May 1st 2025.")]
     public bool IsDeleted { get; private set; }
 
     /// <summary>
@@ -114,7 +114,7 @@ public OpenAIAssistantAgent(
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="OpenAIAssistantAgent"/> instance.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAI.Assistants.AssistantClient to create an assistant (CreateAssistantFromTemplateAsync).")]
+    [Obsolete("Use the OpenAI.Assistants.AssistantClient to create an assistant (CreateAssistantFromTemplateAsync). This method will be removed after May 1st 2025.")]
     public static async Task<OpenAIAssistantAgent> CreateFromTemplateAsync(
 #pragma warning disable SKEXP0110 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
         OpenAIClientProvider clientProvider,
@@ -164,7 +164,7 @@ public static async Task<OpenAIAssistantAgent> CreateFromTemplateAsync(
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="OpenAIAssistantAgent"/> instance.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAI.Assistants.AssistantClient to create an assistant (CreateAssistantAsync).")]
+    [Obsolete("Use the OpenAI.Assistants.AssistantClient to create an assistant (CreateAssistantAsync). This method will be removed after May 1st 2025.")]
     public static async Task<OpenAIAssistantAgent> CreateAsync(
 #pragma warning disable SKEXP0110 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
         OpenAIClientProvider clientProvider,
@@ -202,7 +202,7 @@ public static async Task<OpenAIAssistantAgent> CreateAsync(
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>A list of <see cref="OpenAIAssistantDefinition"/> objects.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAI.Assistants.AssistantClient to query for assistant definitions (GetAssistantsAsync).")]
+    [Obsolete("Use the OpenAI.Assistants.AssistantClient to query for assistant definitions (GetAssistantsAsync). This method will be removed after May 1st 2025.")]
     public static async IAsyncEnumerable<OpenAIAssistantDefinition> ListDefinitionsAsync(
 #pragma warning disable SKEXP0110 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
         OpenAIClientProvider clientProvider,
@@ -230,7 +230,7 @@ public static async IAsyncEnumerable<OpenAIAssistantDefinition> ListDefinitionsA
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An <see cref="OpenAIAssistantAgent"/> instance.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAI.Assistants.AssistantClient to retrieve an assistant definition (GetAssistantsAsync).")]
+    [Obsolete("Use the OpenAI.Assistants.AssistantClient to retrieve an assistant definition (GetAssistantsAsync). This method will be removed after May 1st 2025.")]
     public static async Task<OpenAIAssistantAgent> RetrieveAsync(
 #pragma warning disable SKEXP0110 // Type is for evaluation purposes only and is subject to change or removal in future updates. Suppress this diagnostic to proceed.
         OpenAIClientProvider clientProvider,
@@ -274,7 +274,7 @@ public static async Task<OpenAIAssistantAgent> RetrieveAsync(
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>The thread identifier.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAIAssistantAgentThread to create a thread or use invoke without a thread to create a new one.")]
+    [Obsolete("Use the OpenAIAssistantAgentThread to create a thread or use invoke without a thread to create a new one. This method will be removed after May 1st 2025.")]
     public Task<string> CreateThreadAsync(CancellationToken cancellationToken = default)
         => this.CreateThreadAsync(options: null, cancellationToken);
 
@@ -285,7 +285,7 @@ public Task<string> CreateThreadAsync(CancellationToken cancellationToken = defa
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>The thread identifier.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAIAssistantAgentThread to create a thread or use invoke without a thread to create a new one.")]
+    [Obsolete("Use the OpenAIAssistantAgentThread to create a thread or use invoke without a thread to create a new one. This method will be removed after May 1st 2025.")]
     public Task<string> CreateThreadAsync(OpenAIThreadCreationOptions? options, CancellationToken cancellationToken = default)
         => this.Client.CreateThreadAsync(
             options?.Messages,
@@ -301,7 +301,7 @@ public Task<string> CreateThreadAsync(OpenAIThreadCreationOptions? options, Canc
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>The thread identifier.</returns>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAIAssistantAgentThread to delete an existing thread.")]
+    [Obsolete("Use the OpenAIAssistantAgentThread to delete an existing thread. This method will be removed after May 1st 2025.")]
     public async Task<bool> DeleteThreadAsync(
         string threadId,
         CancellationToken cancellationToken = default)
@@ -323,7 +323,7 @@ public async Task<bool> DeleteThreadAsync(
     /// <remarks>
     /// This method only supports messages with <see href="https://platform.openai.com/docs/api-reference/runs/createRun#runs-createrun-additional_messages">role = User or Assistant</see>.
     /// </remarks>
-    [Obsolete("Pass messages directly to Invoke instead.")]
+    [Obsolete("Pass messages directly to Invoke instead. This method will be removed after May 1st 2025.")]
     public Task AddChatMessageAsync(string threadId, ChatMessageContent message, CancellationToken cancellationToken = default)
     {
         return AssistantThreadActions.CreateMessageAsync(this.Client, threadId, message, cancellationToken);
@@ -335,7 +335,7 @@ public Task AddChatMessageAsync(string threadId, ChatMessageContent message, Can
     /// <param name="threadId">The thread identifier.</param>
     /// <param name="cancellationToken">The <see cref="CancellationToken"/> to monitor for cancellation requests. The default is <see cref="CancellationToken.None"/>.</param>
     /// <returns>An asynchronous enumeration of messages.</returns>
-    [Obsolete("Use the OpenAIAssistantAgentThread to retrieve messages instead.")]
+    [Obsolete("Use the OpenAIAssistantAgentThread to retrieve messages instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> GetThreadMessagesAsync(string threadId, CancellationToken cancellationToken = default)
     {
         return AssistantThreadActions.GetMessagesAsync(this.Client, threadId, null, cancellationToken);
@@ -350,7 +350,7 @@ public IAsyncEnumerable<ChatMessageContent> GetThreadMessagesAsync(string thread
     /// An assistant-based agent is not usable after deletion.
     /// </remarks>
     [Experimental("SKEXP0110")]
-    [Obsolete("Use the OpenAI.Assistants.AssistantClient to remove or otherwise modify the Assistant definition.")]
+    [Obsolete("Use the OpenAI.Assistants.AssistantClient to remove or otherwise modify the Assistant definition. This method will be removed after May 1st 2025.")]
     public async Task<bool> DeleteAsync(CancellationToken cancellationToken = default)
     {
         if (!this.IsDeleted)
@@ -460,7 +460,7 @@ async IAsyncEnumerable<ChatMessageContent> InternalInvokeAsync()
     /// <remarks>
     /// The "arguments" parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         string threadId,
         KernelArguments? arguments = null,
@@ -480,7 +480,7 @@ public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
     /// <remarks>
     /// The "arguments" parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<ChatMessageContent> InvokeAsync(
         string threadId,
         RunCreationOptions? options,
@@ -597,7 +597,7 @@ public async IAsyncEnumerable<AgentResponseItem<StreamingChatMessageContent>> In
     /// <remarks>
     /// The "arguments" parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         string threadId,
         KernelArguments? arguments = null,
@@ -619,7 +619,7 @@ public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
     /// <remarks>
     /// The "arguments" parameter is not currently used by the agent, but is provided for future extensibility.
     /// </remarks>
-    [Obsolete("Use InvokeStreamingAsync with AgentThread instead.")]
+    [Obsolete("Use InvokeStreamingAsync with AgentThread instead. This method will be removed after May 1st 2025.")]
     public IAsyncEnumerable<StreamingChatMessageContent> InvokeStreamingAsync(
         string threadId,
         RunCreationOptions? options,