fix: ensure consistent output for structured content in tool conversion

Author: jeff52415

langchain_mcp_adapters/tools.py

@@ -31,11 +31,7 @@
 NonTextContent: TypeAlias = ImageContent | EmbeddedResource | TextResourceContents
 MAX_ITERATIONS = 1000
 
-# Define at module level
-JSONValue: TypeAlias = (
-    str | int | float | bool | None |
-    dict[str, "JSONValue"] | list["JSONValue"]
-)
+
 
 
 def _convert_call_tool_result(
@@ -68,10 +64,6 @@ def _convert_call_tool_result(
         raise ToolException(tool_content)
 
     artifact = _build_artifact(non_text_contents, call_tool_result)
-    structured = getattr(call_tool_result, "structuredContent", None)
-
-    if structured is not None:
-        return _add_structured_content_to_result(tool_content, structured, artifact)
 
     return tool_content, (artifact if artifact else None)
 
@@ -118,22 +110,6 @@ def _build_artifact(
     return artifact
 
 
-def _add_structured_content_to_result(
-    tool_content: str | list[str],
-    structured: JSONValue,
-    artifact: dict[str, Any],
-) -> tuple[list[Any], dict[str, Any] | None]:
-    """Add structured content to result as JSON block."""
-    content_blocks: list[Any] = []
-    if isinstance(tool_content, str):
-        if tool_content:
-            content_blocks.append(tool_content)
-    else:
-        content_blocks.extend(tool_content)
-    content_blocks.append({"type": "json", "structured": structured})
-    return content_blocks, (artifact if artifact else None)
-
-
 async def _list_all_tools(session: ClientSession) -> list[MCPTool]:
     """List all available tools from an MCP session with pagination support.
 

tests/test_tools.py

@@ -466,15 +466,14 @@ def test_convert_with_structured_content():
     )
     result.structuredContent = structured_data
 
-    content_blocks, artifact = _convert_call_tool_result(result)
+    text_content, artifact = _convert_call_tool_result(result)
 
-    assert content_blocks[0] == "Search completed"
-    assert content_blocks[1] == {"type": "json", "structured": structured_data}
+    assert text_content == "Search completed"
     assert artifact["structuredContent"] == structured_data
 
 
 def test_convert_structured_content_includes_json_block():
-    """Test that structuredContent is included as JSON block in content."""
+    """Test that structuredContent is included in artifact only."""
     structured_data = {"result": "success"}
 
     result = CallToolResult(
@@ -483,11 +482,11 @@ def test_convert_structured_content_includes_json_block():
     )
     result.structuredContent = structured_data
 
-    content_blocks, artifact = _convert_call_tool_result(result)
+    content, artifact = _convert_call_tool_result(result)
 
-    assert isinstance(content_blocks, list)
-    assert content_blocks[0] == "Done"
-    assert content_blocks[1] == {"type": "json", "structured": structured_data}
+    # Content stays simple - just the text
+    assert content == "Done"
+    # Structured data goes in artifact
     assert artifact["structuredContent"] == structured_data
 
 
@@ -498,7 +497,9 @@ def test_convert_with_structured_content_only():
     result = CallToolResult(content=[], isError=False)
     result.structuredContent = structured_data
 
-    content_blocks, artifact = _convert_call_tool_result(result)
+    content, artifact = _convert_call_tool_result(result)
 
-    assert content_blocks == [{"type": "json", "structured": structured_data}]
+    # Empty text content returns empty string
+    assert content == ""
+    # Structured data goes in artifact
     assert artifact["structuredContent"] == structured_data