.NET: Improve session cast error message quality and consistency (#3973)

westey-m · web-flow · commit 08275f657b1b · 2026-02-17T15:51:30.000Z
* Improve session cast error messge consistency

* Update changelog
diff --git a/dotnet/src/Microsoft.Agents.AI.A2A/A2AAgent.cs b/dotnet/src/Microsoft.Agents.AI.A2A/A2AAgent.cs
@@ -81,7 +81,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not A2AAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(A2AAgentSession)}' can be serialized by this agent.");
         }
 
         return new(typedSession.Serialize(jsonSerializerOptions));
@@ -256,7 +256,7 @@ private async ValueTask<A2AAgentSession> GetA2ASessionAsync(AgentSession? sessio
 
         if (session is not A2AAgentSession typedSession)
         {
-            throw new InvalidOperationException($"The provided session type {session.GetType()} is not compatible with the agent. Only A2A agent created sessions are supported.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(A2AAgentSession)}' can be used by this agent.");
         }
 
         return typedSession;
diff --git a/dotnet/src/Microsoft.Agents.AI.CopilotStudio/CopilotStudioAgent.cs b/dotnet/src/Microsoft.Agents.AI.CopilotStudio/CopilotStudioAgent.cs
@@ -60,7 +60,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not CopilotStudioAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(CopilotStudioAgentSession)}' can be serialized by this agent.");
         }
 
         return new(typedSession.Serialize(jsonSerializerOptions));
@@ -84,7 +84,7 @@ protected override async Task<AgentResponse> RunCoreAsync(
         session ??= await this.CreateSessionAsync(cancellationToken).ConfigureAwait(false);
         if (session is not CopilotStudioAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be used.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(CopilotStudioAgentSession)}' can be used by this agent.");
         }
 
         typedSession.ConversationId ??= await this.StartNewConversationAsync(cancellationToken).ConfigureAwait(false);
@@ -123,7 +123,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA
         session ??= await this.CreateSessionAsync(cancellationToken).ConfigureAwait(false);
         if (session is not CopilotStudioAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be used.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(CopilotStudioAgentSession)}' can be used by this agent.");
         }
 
         typedSession.ConversationId ??= await this.StartNewConversationAsync(cancellationToken).ConfigureAwait(false);
diff --git a/dotnet/src/Microsoft.Agents.AI.DurableTask/CHANGELOG.md b/dotnet/src/Microsoft.Agents.AI.DurableTask/CHANGELOG.md
@@ -14,6 +14,7 @@
 - Changed AIAgent.SerializeSession to AIAgent.SerializeSessionAsync ([#3879](https://github.com/microsoft/agent-framework/pull/3879))
 - Changed ChatHistory and AIContext Providers to have pipeline semantics ([#3806](https://github.com/microsoft/agent-framework/pull/3806))
 - Marked all `RunAsync<T>` overloads as `new`, added missing ones, and added support for primitives and arrays ([#3803](https://github.com/microsoft/agent-framework/pull/3803))
+- Improve session cast error message quality and consistency ([#3973](https://github.com/microsoft/agent-framework/pull/3973))
 
 ## v1.0.0-preview.251204.1
 
diff --git a/dotnet/src/Microsoft.Agents.AI.DurableTask/DurableAIAgent.cs b/dotnet/src/Microsoft.Agents.AI.DurableTask/DurableAIAgent.cs
@@ -55,7 +55,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not DurableAgentSession durableSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(DurableAgentSession)}' can be serialized by this agent.");
         }
 
         return new(durableSession.Serialize(jsonSerializerOptions));
diff --git a/dotnet/src/Microsoft.Agents.AI.DurableTask/DurableAIAgentProxy.cs b/dotnet/src/Microsoft.Agents.AI.DurableTask/DurableAIAgentProxy.cs
@@ -20,7 +20,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not DurableAgentSession durableSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(DurableAgentSession)}' can be serialized by this agent.");
         }
 
         return new(durableSession.Serialize(jsonSerializerOptions));
diff --git a/dotnet/src/Microsoft.Agents.AI.GitHub.Copilot/GitHubCopilotAgent.cs b/dotnet/src/Microsoft.Agents.AI.GitHub.Copilot/GitHubCopilotAgent.cs
@@ -104,7 +104,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not GitHubCopilotAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(GitHubCopilotAgentSession)}' can be serialized by this agent.");
         }
 
         return new(typedSession.Serialize(jsonSerializerOptions));
@@ -139,7 +139,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA
         if (session is not GitHubCopilotAgentSession typedSession)
         {
             throw new InvalidOperationException(
-                $"The provided session type {session.GetType()} is not compatible with the agent. Only GitHub Copilot agent created sessions are supported.");
+                $"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(GitHubCopilotAgentSession)}' can be used by this agent.");
         }
 
         // Ensure the client is started
diff --git a/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowHostAgent.cs b/dotnet/src/Microsoft.Agents.AI.Workflows/WorkflowHostAgent.cs
@@ -74,7 +74,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not WorkflowSession workflowSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(WorkflowSession)}' can be serialized by this agent.");
         }
 
         return new(workflowSession.Serialize(jsonSerializerOptions));
diff --git a/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgent.cs b/dotnet/src/Microsoft.Agents.AI/ChatClient/ChatClientAgent.cs
@@ -366,7 +366,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
 
         if (session is not ChatClientAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(ChatClientAgentSession)}' can be serialized by this agent.");
         }
 
         return new(typedSession.Serialize(jsonSerializerOptions));
@@ -674,7 +674,7 @@ private async Task
         session ??= await this.CreateSessionAsync(cancellationToken).ConfigureAwait(false);
         if (session is not ChatClientAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be used.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(ChatClientAgentSession)}' can be used by this agent.");
         }
 
         // Supplying messages when continuing a background response is not allowed.
diff --git a/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/BasicStreamingTests.cs b/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/BasicStreamingTests.cs
@@ -357,7 +357,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
     {
         if (session is not FakeAgentSession fakeSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(FakeAgentSession)}' can be serialized by this agent.");
         }
 
         return new(JsonSerializer.SerializeToElement(fakeSession, jsonSerializerOptions));
diff --git a/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/ForwardedPropertiesTests.cs b/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/ForwardedPropertiesTests.cs
@@ -345,7 +345,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
     {
         if (session is not FakeAgentSession fakeSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(FakeAgentSession)}' can be serialized by this agent.");
         }
 
         return new(JsonSerializer.SerializeToElement(fakeSession, jsonSerializerOptions));
diff --git a/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/SharedStateTests.cs b/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.IntegrationTests/SharedStateTests.cs
@@ -428,7 +428,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
     {
         if (session is not FakeAgentSession fakeSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(FakeAgentSession)}' can be serialized by this agent.");
         }
 
         return new(JsonSerializer.SerializeToElement(fakeSession, jsonSerializerOptions));
diff --git a/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.UnitTests/AGUIEndpointRouteBuilderExtensionsTests.cs b/dotnet/tests/Microsoft.Agents.AI.Hosting.AGUI.AspNetCore.UnitTests/AGUIEndpointRouteBuilderExtensionsTests.cs
@@ -436,7 +436,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
         {
             if (session is not TestAgentSession testSession)
             {
-                throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+                throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(TestAgentSession)}' can be serialized by this agent.");
             }
 
             return new(JsonSerializer.SerializeToElement(testSession, jsonSerializerOptions));
@@ -535,7 +535,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
         {
             if (session is not TestAgentSession testSession)
             {
-                throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+                throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(TestAgentSession)}' can be serialized by this agent.");
             }
 
             return new(JsonSerializer.SerializeToElement(testSession, jsonSerializerOptions));
diff --git a/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/TestEchoAgent.cs b/dotnet/tests/Microsoft.Agents.AI.Workflows.UnitTests/TestEchoAgent.cs
@@ -28,7 +28,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession
     {
         if (session is not EchoAgentSession typedSession)
         {
-            throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");
+            throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(EchoAgentSession)}' can be serialized by this agent.");
         }
 
         return new(JsonSerializer.SerializeToElement(typedSession, jsonSerializerOptions));

Original file line number	Diff line number	Diff line change
`@@ -81,7 +81,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`81`	`81`
`82`	`82`	`if (session is not A2AAgentSession typedSession)`
`83`	`83`	`{`
`84`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`84`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(A2AAgentSession)}' can be serialized by this agent.");`
`85`	`85`	`}`
`86`	`86`
`87`	`87`	`return new(typedSession.Serialize(jsonSerializerOptions));`
`@@ -256,7 +256,7 @@ private async ValueTask<A2AAgentSession> GetA2ASessionAsync(AgentSession? sessio`
`256`	`256`
`257`	`257`	`if (session is not A2AAgentSession typedSession)`
`258`	`258`	`{`
`259`		`- throw new InvalidOperationException($"The provided session type {session.GetType()} is not compatible with the agent. Only A2A agent created sessions are supported.");`
	`259`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(A2AAgentSession)}' can be used by this agent.");`
`260`	`260`	`}`
`261`	`261`
`262`	`262`	`return typedSession;`
Original file line number	Diff line number	Diff line change
`@@ -60,7 +60,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`60`	`60`
`61`	`61`	`if (session is not CopilotStudioAgentSession typedSession)`
`62`	`62`	`{`
`63`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`63`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(CopilotStudioAgentSession)}' can be serialized by this agent.");`
`64`	`64`	`}`
`65`	`65`
`66`	`66`	`return new(typedSession.Serialize(jsonSerializerOptions));`
`@@ -84,7 +84,7 @@ protected override async Task<AgentResponse> RunCoreAsync(`
`84`	`84`	`session ??= await this.CreateSessionAsync(cancellationToken).ConfigureAwait(false);`
`85`	`85`	`if (session is not CopilotStudioAgentSession typedSession)`
`86`	`86`	`{`
`87`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be used.");`
	`87`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(CopilotStudioAgentSession)}' can be used by this agent.");`
`88`	`88`	`}`
`89`	`89`
`90`	`90`	`typedSession.ConversationId ??= await this.StartNewConversationAsync(cancellationToken).ConfigureAwait(false);`
`@@ -123,7 +123,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA`
`123`	`123`	`session ??= await this.CreateSessionAsync(cancellationToken).ConfigureAwait(false);`
`124`	`124`	`if (session is not CopilotStudioAgentSession typedSession)`
`125`	`125`	`{`
`126`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be used.");`
	`126`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(CopilotStudioAgentSession)}' can be used by this agent.");`
`127`	`127`	`}`
`128`	`128`
`129`	`129`	`typedSession.ConversationId ??= await this.StartNewConversationAsync(cancellationToken).ConfigureAwait(false);`
Original file line number	Diff line number	Diff line change
`@@ -55,7 +55,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`55`	`55`
`56`	`56`	`if (session is not DurableAgentSession durableSession)`
`57`	`57`	`{`
`58`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`58`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(DurableAgentSession)}' can be serialized by this agent.");`
`59`	`59`	`}`
`60`	`60`
`61`	`61`	`return new(durableSession.Serialize(jsonSerializerOptions));`
Original file line number	Diff line number	Diff line change
`@@ -20,7 +20,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`20`	`20`
`21`	`21`	`if (session is not DurableAgentSession durableSession)`
`22`	`22`	`{`
`23`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`23`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(DurableAgentSession)}' can be serialized by this agent.");`
`24`	`24`	`}`
`25`	`25`
`26`	`26`	`return new(durableSession.Serialize(jsonSerializerOptions));`
Original file line number	Diff line number	Diff line change
`@@ -104,7 +104,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`104`	`104`
`105`	`105`	`if (session is not GitHubCopilotAgentSession typedSession)`
`106`	`106`	`{`
`107`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`107`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(GitHubCopilotAgentSession)}' can be serialized by this agent.");`
`108`	`108`	`}`
`109`	`109`
`110`	`110`	`return new(typedSession.Serialize(jsonSerializerOptions));`
`@@ -139,7 +139,7 @@ protected override async IAsyncEnumerable<AgentResponseUpdate> RunCoreStreamingA`
`139`	`139`	`if (session is not GitHubCopilotAgentSession typedSession)`
`140`	`140`	`{`
`141`	`141`	`throw new InvalidOperationException(`
`142`		`- $"The provided session type {session.GetType()} is not compatible with the agent. Only GitHub Copilot agent created sessions are supported.");`
	`142`	`+ $"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(GitHubCopilotAgentSession)}' can be used by this agent.");`
`143`	`143`	`}`
`144`	`144`
`145`	`145`	`// Ensure the client is started`
Original file line number	Diff line number	Diff line change
`@@ -74,7 +74,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`74`	`74`
`75`	`75`	`if (session is not WorkflowSession workflowSession)`
`76`	`76`	`{`
`77`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`77`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(WorkflowSession)}' can be serialized by this agent.");`
`78`	`78`	`}`
`79`	`79`
`80`	`80`	`return new(workflowSession.Serialize(jsonSerializerOptions));`
Original file line number	Diff line number	Diff line change
`@@ -366,7 +366,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`366`	`366`
`367`	`367`	`if (session is not ChatClientAgentSession typedSession)`
`368`	`368`	`{`
`369`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`369`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(ChatClientAgentSession)}' can be serialized by this agent.");`
`370`	`370`	`}`
`371`	`371`
`372`	`372`	`return new(typedSession.Serialize(jsonSerializerOptions));`
`@@ -674,7 +674,7 @@ private async Task`
`674`	`674`	`session ??= await this.CreateSessionAsync(cancellationToken).ConfigureAwait(false);`
`675`	`675`	`if (session is not ChatClientAgentSession typedSession)`
`676`	`676`	`{`
`677`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be used.");`
	`677`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(ChatClientAgentSession)}' can be used by this agent.");`
`678`	`678`	`}`
`679`	`679`
`680`	`680`	`// Supplying messages when continuing a background response is not allowed.`
Original file line number	Diff line number	Diff line change
`@@ -357,7 +357,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`357`	`357`	`{`
`358`	`358`	`if (session is not FakeAgentSession fakeSession)`
`359`	`359`	`{`
`360`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`360`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(FakeAgentSession)}' can be serialized by this agent.");`
`361`	`361`	`}`
`362`	`362`
`363`	`363`	`return new(JsonSerializer.SerializeToElement(fakeSession, jsonSerializerOptions));`
Original file line number	Diff line number	Diff line change
`@@ -345,7 +345,7 @@ protected override ValueTask<JsonElement> SerializeSessionCoreAsync(AgentSession`
`345`	`345`	`{`
`346`	`346`	`if (session is not FakeAgentSession fakeSession)`
`347`	`347`	`{`
`348`		`- throw new InvalidOperationException("The provided session is not compatible with the agent. Only sessions created by the agent can be serialized.");`
	`348`	`+ throw new InvalidOperationException($"The provided session type '{session.GetType().Name}' is not compatible with this agent. Only sessions of type '{nameof(FakeAgentSession)}' can be serialized by this agent.");`
`349`	`349`	`}`
`350`	`350`
`351`	`351`	`return new(JsonSerializer.SerializeToElement(fakeSession, jsonSerializerOptions));`