Factor ChatOptions.Instructions into PersistentAgentsChatClient (Azure#51180)

* Factor ChatOptions.Instructions into PersistentAgentsChatClient

* Small fix

---------

Co-authored-by: Dmytro Struk <[email protected]>

Author: stephentoub

eng/Packages.Data.props

@@ -207,7 +207,7 @@
   </ItemGroup>
 
   <ItemGroup Condition="$(MSBuildProjectName.Contains('Azure.AI.Agents.Persistent'))">
-    <PackageReference Update="Microsoft.Extensions.AI.Abstractions" Version="9.6.0"/>
+    <PackageReference Update="Microsoft.Extensions.AI.Abstractions" Version="9.7.0"/>
   </ItemGroup>
 
   <ItemGroup Condition="$(MSBuildProjectName.Contains('Azure.Projects'))">

sdk/ai/Azure.AI.Agents.Persistent/assets.json

@@ -2,5 +2,5 @@
   "AssetsRepo": "Azure/azure-sdk-assets",
   "AssetsRepoPrefixPath": "net",
   "TagPrefix": "net/ai/Azure.AI.Agents.Persistent",
-  "Tag": "net/ai/Azure.AI.Agents.Persistent_ee70790a0c"
+  "Tag": "net/ai/Azure.AI.Agents.Persistent_566ea3f825"
 }

sdk/ai/Azure.AI.Agents.Persistent/src/Custom/PersistentAgentsChatClient.cs

@@ -35,8 +35,8 @@ internal partial class PersistentAgentsChatClient : IChatClient
         /// <summary>The thread ID to use if none is supplied in <see cref="ChatOptions.ConversationId"/>.</summary>
         private readonly string? _defaultThreadId;
 
-        /// <summary>List of tools associated with the agent.</summary>
-        private IReadOnlyList<ToolDefinition>? _agentTools;
+        /// <summary>Lazily-retrieved agent instance. Used for its properties.</summary>
+        private PersistentAgent? _agent;
 
         /// <summary>Initializes a new instance of the <see cref="PersistentAgentsChatClient"/> class for the specified <see cref="PersistentAgentsClient"/>.</summary>
         public PersistentAgentsChatClient(PersistentAgentsClient client, string agentId, string? defaultThreadId = null)
@@ -233,6 +233,13 @@ public void Dispose() { }
                 options?.RawRepresentationFactory?.Invoke(this) as ThreadAndRunOptions ??
                 new();
 
+            // Load details about the agent if not already loaded.
+            if (_agent is null)
+            {
+                PersistentAgent agent = await _client!.Administration.GetAgentAsync(_agentId, cancellationToken).ConfigureAwait(false);
+                Interlocked.CompareExchange(ref _agent, agent, null);
+            }
+
             // Populate the run options from the ChatOptions, if provided.
             if (options is not null)
             {
@@ -253,13 +260,7 @@ public void Dispose() { }
                     // along with our tools.
                     if (runOptions.OverrideTools is null || !runOptions.OverrideTools.Any())
                     {
-                        if (_agentTools is null)
-                        {
-                            PersistentAgent agent = await _client!.Administration.GetAgentAsync(_agentId, cancellationToken).ConfigureAwait(false);
-                            _agentTools = agent.Tools;
-                        }
-
-                        toolDefinitions.AddRange(_agentTools);
+                        toolDefinitions.AddRange(_agent.Tools);
                     }
 
                     // The caller can provide tools in the supplied ThreadAndRunOptions.
@@ -337,6 +338,18 @@ public void Dispose() { }
 
             runOptions.ThreadOptions ??= new();
 
+            bool treatInstructionsAsOverride = false;
+            if (runOptions.OverrideInstructions is not null)
+            {
+                treatInstructionsAsOverride = true;
+                (instructions ??= new()).Append(runOptions.OverrideInstructions);
+            }
+
+            if (options?.Instructions is not null)
+            {
+                (instructions ??= new()).Append(options.Instructions);
+            }
+
             foreach (ChatMessage chatMessage in messages)
             {
                 List<MessageInputContentBlock> messageContents = [];
@@ -392,6 +405,14 @@ public void Dispose() { }
 
             if (instructions is not null)
             {
+                // If runOptions.OverrideInstructions was set by the caller, then all instructions are treated
+                // as an override. Otherwise, we want all of the instructions to augment the agent's instructions,
+                // so insert the agent's at the beginning.
+                if (!treatInstructionsAsOverride && !string.IsNullOrEmpty(_agent.Instructions))
+                {
+                    instructions.Insert(0, _agent.Instructions);
+                }
+
                 runOptions.OverrideInstructions = instructions.ToString();
             }
 

sdk/ai/Azure.AI.Agents.Persistent/tests/PersistentAgentsChatClientTests.cs

@@ -339,7 +339,7 @@ public void Cleanup()
             Pageable<PersistentAgent> agents = client.Administration.GetAgents();
             foreach (PersistentAgent agent in agents)
             {
-                if (agent.Name.StartsWith(AGENT_NAME))
+                if (agent.Name is not null && agent.Name.StartsWith(AGENT_NAME))
                     client.Administration.DeleteAgent(agent.Id);
             }