Use custom format_output_for_agent override for tool output

When a `BaseTool` subclass overrides `format_output_for_agent`, route
the agent-facing text through it instead of the default JSON/`str()`
serialization. The structured tool wrapper now delegates to the original
tool via `_original_tool`, so a tool can present Markdown or any custom
representation to the agent while `tool.run(...)` still returns the raw
Python value.

lib/crewai/src/crewai/tools/structured_tool.py

@@ -52,6 +52,10 @@ def _infer_output_schema_from_callable(
 
 
 def _format_tool_output_for_agent(tool: Any, raw_result: Any) -> str:
+    original_tool = getattr(tool, "_original_tool", None)
+    if original_tool is not None:
+        return cast(str, original_tool.format_output_for_agent(raw_result))
+
     output_schema = getattr(tool, "output_schema", None)
     if output_schema is None:
         return str(raw_result)

lib/crewai/tests/tools/test_base_tool.py

@@ -584,6 +584,30 @@ class TestToolOutputSchema:
             "score": 0.8,
         }
 
+    def test_custom_agent_output_formatter_carries_over_to_structured_tool(
+        self,
+    ) -> None:
+        class MarkdownSearchTool(BaseTool):
+            name: str = "markdown_search"
+            description: str = "Search for information"
+            output_schema: type[BaseModel] = SearchOutput
+
+            def _run(self, query: str) -> SearchOutput:
+                return SearchOutput(query=query, score=0.8)
+
+            def format_output_for_agent(self, raw_result: object) -> str:
+                result = self.output_schema.model_validate(raw_result)
+                return f"### Search result\n\n- Query: `{result.query}`\n- Score: {result.score}"
+
+        structured = MarkdownSearchTool().to_structured_tool()
+
+        raw_result = structured.invoke({"query": "crew"})
+
+        assert raw_result == SearchOutput(query="crew", score=0.8)
+        assert structured.format_output_for_agent(raw_result) == (
+            "### Search result\n\n- Query: `crew`\n- Score: 0.8"
+        )
+
 # Async arun() Schema Validation Tests
 
 

lib/crewai/tests/utilities/test_agent_utils.py

@@ -1079,6 +1079,51 @@ class TestExecuteSingleNativeToolCall:
             "score": 0.9,
         }
 
+    def test_custom_agent_output_formatter_is_used_from_structured_tool(
+        self,
+    ) -> None:
+        clear_before_tool_call_hooks()
+        clear_after_tool_call_hooks()
+
+        class SearchOutput(BaseModel):
+            query: str
+            score: float
+
+        class MarkdownSearchTool(BaseTool):
+            name: str = "markdown_search"
+            description: str = "Search for a query"
+            output_schema: type[BaseModel] = SearchOutput
+
+            def _run(self, query: str) -> SearchOutput:
+                return SearchOutput(query=query, score=0.9)
+
+            def format_output_for_agent(self, raw_result: Any) -> str:
+                result = self.output_schema.model_validate(raw_result)
+                return f"### {result.query}\n\nScore: **{result.score}**"
+
+        tool = MarkdownSearchTool()
+        tool_call = MagicMock()
+        tool_call.id = "call_1"
+        tool_call.function.name = "markdown_search"
+        tool_call.function.arguments = '{"query": "crew"}'
+
+        result = execute_single_native_tool_call(
+            tool_call,
+            available_functions={"markdown_search": tool._run},
+            original_tools=[],
+            structured_tools=[tool.to_structured_tool()],
+            tools_handler=None,
+            agent=None,
+            task=None,
+            crew=None,
+            event_source=MagicMock(),
+            printer=None,
+            verbose=False,
+        )
+
+        assert result.result == "### crew\n\nScore: **0.9**"
+        assert result.tool_message["content"] == "### crew\n\nScore: **0.9**"
+
     def test_after_hook_includes_raw_tool_result_for_typed_output(self) -> None:
         clear_after_tool_call_hooks()