Python: Unify tool results as Content items with rich content support (#4331)

* feat(python): allow @tool functions to return rich content (images, audio)

Add support for tool functions to return Content objects that the model can perceive natively. Closes #4272

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

* Anthropic logging + mypy fix

* Address PR review: fix MCP ordering, fold helper into from_function_result, fix Chat client

- Preserve original content order in MCP tool results instead of text-first
- Move _build_function_result logic into Content.from_function_result()
- Chat Completions: inject user message for rich items (API only supports string tool content)
- Update tests for ordering and new from_function_result behavior

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

* Use native Responses API multi-part output, warn+omit for Chat client

- Responses client: put rich items directly in function_call_output's
  output field as list (native API support) instead of user message injection
- Chat client: warn and omit rich items (API doesn't support multi-part
  tool results), matching Ollama/Bedrock pattern
- Unify test image: use sample_image.jpg across all integration tests
- Add Azure OpenAI Responses integration test
- Assert model describes house image to verify perception

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

* Fix lint: remove print statement, wrap long line

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

* Address review feedback: bug fixes, single-pass MCP, unit tests

- Add isinstance guard in from_function_result for non-Content lists
- Fix Anthropic empty tool_content fallback to string result
- Fix Content(type='text', text=None) edge case in parse_result
- Rewrite MCP _parse_tool_result_from_mcp as single-pass (no index counters)
- Add Anthropic unit tests: data image, uri image, unsupported media, all-unsupported
- Add OpenAI Chat unit test: rich items warning and omission
- Add OpenAI Responses unit tests: function_result with/without items
- Add test_types tests: only-rich-items list, non-Content list fallback

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

* Fix pyright errors: add type ignore comments for Any list iteration

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

* Fix mypy/pyright: ensure ToolExecutionException receives str

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

* Fix lint: remove duplicate test_prepare_options_excludes_conversation_id

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

* refactor: unify all tool results into Content items

* addressed copilot comments

* pyright fix

* small fix

* comments

* fix: address Copilot review - warnings, blob safety, dedup

- Add warning logs when rich content is dropped in Claude agent and
  MCP server handlers (matching Chat/Bedrock/Ollama pattern)
- Defensive blob URI construction: wrap plain base64 in data: prefix
- Simplify Chat client _prepare_content_for_openai to use content.result
- Simplify Responses client text-only path, remove redundant nesting
- Add test for plain base64 blob without data: prefix

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

* Fix token double-counting in compaction and address review comments

- Exclude items from _serialize_content() to prevent double-counting
  tokens when items mirrors result in function_result content
- Add rich content warning in GitHub Copilot agent tool handler
- Replace raw Content debug log with concise item count/type summary
- Update stale test comments about FunctionTool.invoke return type

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

---------

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

Author: giles17

python/packages/ag-ui/tests/ag_ui/test_event_converters.py

@@ -185,7 +185,7 @@ def test_tool_call_result_event(self) -> None:
         assert update.role == "tool"
         assert len(update.contents) == 1
         assert update.contents[0].call_id == "call_123"
-        assert update.contents[0].result == {"temperature": 22, "condition": "sunny"}
+        assert update.contents[0].result == '{"temperature": 22, "condition": "sunny"}'
 
     def test_run_finished_event(self) -> None:
         """Test conversion of RUN_FINISHED event."""

python/packages/anthropic/agent_framework_anthropic/_chat_client.py

@@ -716,12 +716,46 @@ def _prepare_message_for_anthropic(self, message: Message) -> dict[str, Any]:
                         "input": content.parse_arguments(),
                     })
                 case "function_result":
-                    a_content.append({
-                        "type": "tool_result",
-                        "tool_use_id": content.call_id,
-                        "content": content.result if content.result is not None else "",
-                        "is_error": content.exception is not None,
-                    })
+                    if content.items:
+                        tool_content: list[dict[str, Any]] = []
+                        for item in content.items:
+                            if item.type == "text":
+                                tool_content.append({"type": "text", "text": item.text or ""})
+                            elif item.type == "data" and item.has_top_level_media_type("image"):
+                                tool_content.append({
+                                    "type": "image",
+                                    "source": {
+                                        "data": _get_data_bytes_as_str(item),  # type: ignore[attr-defined]
+                                        "media_type": item.media_type,
+                                        "type": "base64",
+                                    },
+                                })
+                            elif item.type == "uri" and item.has_top_level_media_type("image"):
+                                tool_content.append({
+                                    "type": "image",
+                                    "source": {"type": "url", "url": item.uri},
+                                })
+                            else:
+                                logger.debug(
+                                    "Ignoring unsupported rich content media type in tool result: %s",
+                                    item.media_type,
+                                )
+                        tool_result_content = (
+                            tool_content if tool_content else (content.result if content.result is not None else "")
+                        )
+                        a_content.append({
+                            "type": "tool_result",
+                            "tool_use_id": content.call_id,
+                            "content": tool_result_content,
+                            "is_error": content.exception is not None,
+                        })
+                    else:
+                        a_content.append({
+                            "type": "tool_result",
+                            "tool_use_id": content.call_id,
+                            "content": content.result if content.result is not None else "",
+                            "is_error": content.exception is not None,
+                        })
                 case "mcp_server_tool_call":
                     mcp_call: dict[str, Any] = {
                         "type": "mcp_tool_use",