From e40b29b5f5a0b469b730f55268c0a5ca01621c3c Mon Sep 17 00:00:00 2001
From: Devin AI <158243242+devin-ai-integration[bot]@users.noreply.github.com>
Date: Thu, 2 Apr 2026 23:12:11 +0000
Subject: [PATCH] fix: use None sentinel instead of 'unknown' in
 _extract_tool_name
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Addresses Cursor Bugbot feedback: the string 'unknown' could collide
with a tool legitimately named 'unknown'. Now _extract_tool_name
returns None for unrecognised formats, and _should_parallelize checks
'is None' instead of '== "unknown"'.

Co-Authored-By: João <joao@crewai.com>
---
 .../src/crewai/experimental/agent_executor.py | 19 ++++++++++++-------
 .../tests/agents/test_agent_executor.py       |  8 ++++----
 2 files changed, 16 insertions(+), 11 deletions(-)

diff --git a/lib/crewai/src/crewai/experimental/agent_executor.py b/lib/crewai/src/crewai/experimental/agent_executor.py
index f091648af..1eb4472e6 100644
--- a/lib/crewai/src/crewai/experimental/agent_executor.py
+++ b/lib/crewai/src/crewai/experimental/agent_executor.py
@@ -1690,7 +1690,7 @@ class AgentExecutor(Flow[AgentExecutorState], CrewAgentExecutorMixin):
 
         for tool_call in tool_calls:
             func_name = self._extract_tool_name(tool_call)
-            if func_name == "unknown":
+            if func_name is None:
                 continue
 
             original_tool = self._resolve_original_tool(func_name)
@@ -1908,8 +1908,14 @@ class AgentExecutor(Flow[AgentExecutorState], CrewAgentExecutorMixin):
             "original_tool": original_tool,
         }
 
-    def _extract_tool_name(self, tool_call: Any) -> str:
-        """Extract tool name from various tool call formats."""
+    def _extract_tool_name(self, tool_call: Any) -> str | None:
+        """Extract tool name from various tool call formats.
+
+        Returns:
+            The sanitized tool name, or ``None`` when the format is
+            unrecognised (avoids collisions with a tool legitimately
+            named "unknown").
+        """
         if hasattr(tool_call, "function"):
             return sanitize_tool_name(tool_call.function.name)
         if hasattr(tool_call, "function_call") and tool_call.function_call:
@@ -1918,10 +1924,9 @@ class AgentExecutor(Flow[AgentExecutorState], CrewAgentExecutorMixin):
             return sanitize_tool_name(tool_call.name)
         if isinstance(tool_call, dict):
             func_info = tool_call.get("function", {})
-            return sanitize_tool_name(
-                func_info.get("name", "") or tool_call.get("name", "unknown")
-            )
-        return "unknown"
+            name = func_info.get("name", "") or tool_call.get("name", "")
+            return sanitize_tool_name(name) if name else None
+        return None
 
     @router(execute_native_tool)
     def check_native_todo_completion(
diff --git a/lib/crewai/tests/agents/test_agent_executor.py b/lib/crewai/tests/agents/test_agent_executor.py
index 53aead6f9..ded34e563 100644
--- a/lib/crewai/tests/agents/test_agent_executor.py
+++ b/lib/crewai/tests/agents/test_agent_executor.py
@@ -2141,12 +2141,12 @@ class TestExtractToolName:
 
         assert executor._extract_tool_name(tc) == "bedrock_tool"
 
-    def test_unknown_format_returns_unknown(self, mock_dependencies):
-        """Completely unrecognized object returns 'unknown'."""
+    def test_unknown_format_returns_none(self, mock_dependencies):
+        """Completely unrecognized object returns None (not 'unknown')."""
         executor = _build_executor(**mock_dependencies)
 
-        assert executor._extract_tool_name(42) == "unknown"
-        assert executor._extract_tool_name("not a tool call") == "unknown"
+        assert executor._extract_tool_name(42) is None
+        assert executor._extract_tool_name("not a tool call") is None
 
     def test_sanitizes_names(self, mock_dependencies):
         """Tool names with special characters are sanitized."""