fix vesearch reutrn value name

Author: yaozheng-fang

veadk/tools/builtin_tools/vesearch.py

@@ -32,7 +32,7 @@ def vesearch(query: str) -> str:
     if api_key == "":
         return "Invoke `vesearch` failed. Please set VESEARCH_API_KEY as your environment variable."
     if bot_id == "":
-        return "Invoke `vesearch` failed. Please set VESEARCH_BOT_ID as your environment variable."
+        return "Invoke `vesearch` failed. Please set TOOL_VESEARCH_ENDPOINT as your environment variable."
 
     URL = "https://open.feedcoopapi.com/agent_api/agent/chat/completion"
     headers = {"Authorization": f"Bearer {api_key}", "Content-Type": "application/json"}