fix: Hugging Face MCP calls are not dynamic

CHANGELOG.md

@@ -1148,6 +1148,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Fixed
 
+- Hugging Face MCP calls (`mcp_call`, `mcp_list_tools`) and their results are
+  no longer marked `dynamic`, as in `@ai-sdk/huggingface` 2.0.62. Without a
+  local tool of that name, `generate_text` now returns the call marked invalid
+  (`NoSuchTool`), as the AI SDK's `parseToolCall` does.
 - `default_providers()`, `openai()` and `anthropic()` no longer panic on an
   invalid `OPENAI_BASE_URL` / `ANTHROPIC_BASE_URL`. The variable is still
   read when the provider is created, as the AI SDK does; an invalid value now

aimux-providers/src/huggingface/responses.rs

@@ -1023,7 +1023,7 @@ fn build_generate_content(response: &Value) -> Result<Vec<GenerateContent>, AiMu
                     tool_name: name.to_string(),
                     input,
                     provider_executed: Some(true),
-                    dynamic: Some(true),
+                    dynamic: None,
                     provider_metadata: None,
                 }));
 
@@ -1034,7 +1034,7 @@ fn build_generate_content(response: &Value) -> Result<Vec<GenerateContent>, AiMu
                         result: output.clone(),
                         is_error: None,
                         preliminary: None,
-                        dynamic: Some(true),
+                        dynamic: None,
                         provider_metadata: None,
                     }));
                 }
@@ -1048,7 +1048,7 @@ fn build_generate_content(response: &Value) -> Result<Vec<GenerateContent>, AiMu
                     tool_name: "list_tools".to_string(),
                     input: json!({ "server_label": server_label }).to_string(),
                     provider_executed: Some(true),
-                    dynamic: Some(true),
+                    dynamic: None,
                     provider_metadata: None,
                 }));
 
@@ -1059,7 +1059,7 @@ fn build_generate_content(response: &Value) -> Result<Vec<GenerateContent>, AiMu
                         result: json!({ "tools": tools }),
                         is_error: None,
                         preliminary: None,
-                        dynamic: Some(true),
+                        dynamic: None,
                         provider_metadata: None,
                     }));
                 }

aimux-providers/tests/huggingface_responses_test.rs

@@ -575,14 +575,16 @@ async fn should_handle_mcp_tools_with_annotations() {
         other => panic!("expected Source at [4], got {other:?}"),
     }
 
+    // Like upstream, the MCP call is not dynamic: without a local `search`
+    // tool, Core returns it marked invalid (parseToolCall's NoSuchToolError).
     let result = generate_text(&model, "Hello", GenerateTextOptions::default())
         .await
-        .expect("dynamic MCP call should pass Core validation without local tools");
+        .expect("an unknown tool is an invalid call, not an error");
     let call = *result.tool_calls().first().expect("MCP tool call");
     assert_eq!(call.tool_name, "search");
     assert_eq!(call.provider_executed, Some(true));
     assert_eq!(call.dynamic, Some(true));
-    assert_eq!(call.invalid, None);
+    assert_eq!(call.invalid, Some(true));
     assert_eq!(call.input, json!({ "query": "San Francisco tech events" }));
 }