[EngSys] Agentic Triage tool parameter fix (Azure#57814)

The focus of these changes is to tweak instructions
to ensure that the required parameter for the MCP
tools used by the triage process explicitly detail
the parameters that are expected.  This is to ensure
that the triage process is more reliable, as we've
seen some cases where parameters were not being
included, leading to missed steps.

Author: jsquire

.github/workflows/issue-triage.md

@@ -215,7 +215,9 @@ Note: The gh-aw runtime provides additional baseline defenses including the XPIA
 - If triggered by an `issues.opened` event: the issue number is `${{ github.event.issue.number }}`
 - If triggered by `workflow_dispatch`: the issue number is `${{ github.event.inputs.issue_number }}`
 
-Note the issue number — you must include it as the `issue_number` parameter in every safe-output tool call (add-labels, remove-labels, add-comment, assign-to-user, close-issue)
+Note the issue number — you must include it in every safe-output tool call:
+- For `add-labels`, `remove-labels`, and `add-comment`: pass it as `item_number`
+- For `assign-to-user` and `close-issue`: pass it as `issue_number`
 
 Retrieve the issue using the `get_issue` tool