Add DefaultAzureCredential production warning comments to all HostedAgents samples

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

dotnet/samples/05-end-to-end/HostedAgents/AgentThreadAndHITL/Program.cs

@@ -22,6 +22,9 @@ static string GetWeather([Description("The location to get the weather for.")] s
 // Create the chat client and agent.
 // Note: ApprovalRequiredAIFunction wraps the tool to require user approval before invocation.
 // User should reply with 'approve' or 'reject' when prompted.
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
 #pragma warning disable MEAI001 // Type is for evaluation purposes only
 AIAgent agent = new AzureOpenAIClient(
     new Uri(endpoint),

dotnet/samples/05-end-to-end/HostedAgents/AgentWithHostedMCP/Program.cs

@@ -21,6 +21,9 @@ AITool mcpTool = new HostedMcpServerTool(serverName: "microsoft_learn", serverAd
 };
 
 // Create an agent with the MCP tool using Azure OpenAI Responses.
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
 AIAgent agent = new AzureOpenAIClient(
     new Uri(endpoint),
     new DefaultAzureCredential())

dotnet/samples/05-end-to-end/HostedAgents/AgentWithLocalTools/Program.cs

@@ -84,6 +84,9 @@ string GetAvailableHotels(
     }
 }
 
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
 var credential = new DefaultAzureCredential();
 AIProjectClient projectClient = new(new Uri(endpoint), credential);
 

dotnet/samples/05-end-to-end/HostedAgents/AgentWithTextSearchRag/Program.cs

@@ -20,6 +20,9 @@ TextSearchProviderOptions textSearchOptions = new()
     RecentMessageMemoryLimit = 6,
 };
 
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
 AIAgent agent = new AzureOpenAIClient(
     new Uri(endpoint),
     new DefaultAzureCredential())

dotnet/samples/05-end-to-end/HostedAgents/AgentWithTools/Program.cs

@@ -13,6 +13,9 @@ var openAiEndpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT")
 var deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";
 var toolConnectionId = Environment.GetEnvironmentVariable("MCP_TOOL_CONNECTION_ID") ?? throw new InvalidOperationException("MCP_TOOL_CONNECTION_ID is not set.");
 
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
 var credential = new DefaultAzureCredential();
 
 var chatClient = new AzureOpenAIClient(new Uri(openAiEndpoint), credential)

dotnet/samples/05-end-to-end/HostedAgents/AgentsInWorkflows/Program.cs

@@ -15,6 +15,9 @@ using Microsoft.Extensions.AI;
 var endpoint = Environment.GetEnvironmentVariable("AZURE_OPENAI_ENDPOINT") ?? throw new InvalidOperationException("AZURE_OPENAI_ENDPOINT is not set.");
 var deploymentName = Environment.GetEnvironmentVariable("AZURE_OPENAI_DEPLOYMENT_NAME") ?? "gpt-4o-mini";
 
+// WARNING: DefaultAzureCredential is convenient for development but requires careful consideration in production.
+// In production, consider using a specific credential (e.g., ManagedIdentityCredential) to avoid
+// latency issues, unintended credential probing, and potential security risks from fallback mechanisms.
 IChatClient chatClient = new AzureOpenAIClient(new Uri(endpoint), new DefaultAzureCredential())
     .GetChatClient(deploymentName)
     .AsIChatClient();