Fix trailing commas in agent tools arrays causing empty tool names (#1543)

Three agent files had a trailing comma after the last element in their
YAML flow-sequence tools arrays. When parsed, this produces an empty
string as an extra tool entry, which the Copilot API rejects with:

  CAPIError: 400 Invalid 'tools[N].function.name': empty string

Affected files:
- agents/kusto-assistant.agent.md
- agents/mentoring-juniors.agent.md
- agents/address-comments.agent.md

Co-authored-by: ilderaj <>

agents/kusto-assistant.agent.md

@@ -22,7 +22,7 @@ tools:
     "terminalSelection",
     "testFailure",
     "usages",
-    "vscodeAPI",
+    "vscodeAPI"
   ]
 ---