diff --git a/src/cleveragents/a2a/agent_card.py b/src/cleveragents/a2a/agent_card.py
index 419962d3d..d0a2bfc1b 100644
--- a/src/cleveragents/a2a/agent_card.py
+++ b/src/cleveragents/a2a/agent_card.py
@@ -420,8 +420,7 @@ class AgentCardGenerator:
             raise ValueError("server_url must not be empty")
         if not any(stripped.startswith(scheme) for scheme in self._ALLOWED_SCHEMES):
             raise ValueError(
-                "server_url must start with 'http://' or 'https://', got "
-                f"'{stripped}'"
+                f"server_url must start with 'http://' or 'https://', got '{stripped}'"
             )
         self.server_url = stripped.rstrip("/")
         self.streaming = bool(streaming)