diff --git a/appium/webdriver/webdriver.py b/appium/webdriver/webdriver.py
index 09d17094..5410409e 100644
--- a/appium/webdriver/webdriver.py
+++ b/appium/webdriver/webdriver.py
@@ -314,11 +314,10 @@ def _update_command_executor(self, keep_alive: bool) -> None:
 
         if not self.caps:
             raise ValueError('Driver capabilities must be defined')
-        if not {direct_protocol, direct_host, direct_port, direct_path}.issubset(set(self.caps)):
-            message = 'Direct connect capabilities from server were:\n'
-            for key in [direct_protocol, direct_host, direct_port, direct_path]:
-                message += f"{key}: '{self.caps.get(key, '')}' "
-            logger.debug(message)
+        keys = (direct_protocol, direct_host, direct_port, direct_path)
+        if not set(keys).issubset(self.caps):
+            details = ' '.join(f"{key}: '{self.caps.get(key, '')}'" for key in keys)
+            logger.debug(f'Direct connect capabilities from server were:\n{details} ')
             return
 
         protocol = self.caps[direct_protocol]