Fix type-checker issues in A2A protocol implementation

- Update BaseAgent.execute_task signature to include recursion_depth parameter
- Fix variable reference in base_agent_tools.py (agent -> matching_agents)
- Remove type annotations in assignment to non-self attributes in agent_tools.py

Co-Authored-By: Joe Moura <joao@crewai.com>

src/crewai/agents/agent_builder/base_agent.py

@@ -254,6 +254,7 @@ class BaseAgent(ABC, BaseModel):
         task: Any,
         context: Optional[str] = None,
         tools: Optional[List[BaseTool]] = None,
+        recursion_depth: int = 0,
     ) -> str:
         pass
 

src/crewai/tools/agent_tools/agent_tools.py

@@ -24,14 +24,14 @@ class AgentTools:
             i18n=self.i18n,
             description=self.i18n.tools("delegate_work").format(coworkers=coworkers),  # type: ignore
         )
-        delegate_tool._agent_tools: List[BaseTool] = self._get_all_agent_tools()
+        delegate_tool._agent_tools = self._get_all_agent_tools()
 
         ask_tool = AskQuestionTool(
             agents=self.agents,
             i18n=self.i18n,
             description=self.i18n.tools("ask_question").format(coworkers=coworkers),  # type: ignore
         )
-        ask_tool._agent_tools: List[BaseTool] = self._get_all_agent_tools()
+        ask_tool._agent_tools = self._get_all_agent_tools()
 
         return [delegate_tool, ask_tool]
 

src/crewai/tools/agent_tools/base_agent_tools.py

@@ -108,12 +108,12 @@ class BaseAgentTool(BaseTool):
             available_agents = [agent.role for agent in self.agents]
             logger.debug(f"Available agents: {available_agents}")
 
-            agent = [  # type: ignore # Incompatible types in assignment (expression has type "list[BaseAgent]", variable has type "str | None")
+            matching_agents = [
                 available_agent
                 for available_agent in self.agents
                 if self.sanitize_agent_name(available_agent.role) == sanitized_name
             ]
-            logger.debug(f"Found {len(agent)} matching agents for role '{sanitized_name}'")
+            logger.debug(f"Found {len(matching_agents)} matching agents for role '{sanitized_name}'")
         except (AttributeError, ValueError) as e:
             # Handle specific exceptions that might occur during role name processing
             return self.i18n.errors("agent_tool_unexisting_coworker").format(
@@ -123,7 +123,7 @@ class BaseAgentTool(BaseTool):
                 error=str(e)
             )
 
-        if not agent:
+        if not matching_agents:
             # No matching agent found after sanitization
             return self.i18n.errors("agent_tool_unexisting_coworker").format(
                 coworkers="\n".join(
@@ -132,7 +132,7 @@ class BaseAgentTool(BaseTool):
                 error=f"No agent found with role '{sanitized_name}'"
             )
 
-        agent = agent[0]
+        agent = matching_agents[0]
         try:
             logger.debug(f"Executing task with {len(tools) if tools else 0} tools at recursion depth {recursion_depth}")
             task_with_assigned_agent = Task(