diff --git a/src/crewai/tools/agent_tools.py b/src/crewai/tools/agent_tools.py
index 43796fd64..80754674c 100644
--- a/src/crewai/tools/agent_tools.py
+++ b/src/crewai/tools/agent_tools.py
@@ -47,16 +47,20 @@ class AgentTools(BaseModel):
             agent = [
                 available_agent
                 for available_agent in self.agents
-                if available_agent.role.strip().lower() == agent.strip().lower()
+                if available_agent.role.casefold().strip() == agent.casefold().strip()
             ]
         except:
             return self.i18n.errors("agent_tool_unexsiting_coworker").format(
-                coworkers="\n".join([f"- {agent.role}" for agent in self.agents])
+                coworkers="\n".join(
+                    [f"- {agent.role.casefold()}" for agent in self.agents]
+                )
             )
 
         if not agent:
             return self.i18n.errors("agent_tool_unexsiting_coworker").format(
-                coworkers="\n".join([f"- {agent.role}" for agent in self.agents])
+                coworkers="\n".join(
+                    [f"- {agent.role.casefold()}" for agent in self.agents]
+                )
             )
 
         agent = agent[0]