[All & Namespace mode] `eventhubs_namespace_get` fails for E2E prompt `List all Event Hubs namespaces in my subscription` when `resourceGroup` is missing

[Menghua1]

Description:
In Namespace and All modes, when the E2E prompt List all Event Hubs namespaces in my subscriptions is entered, the tool eventhubs_namespace_get fails due to the missing resourceGroup parameter and ultimately falls back to a another tool response.

Steps to Reproduce:

1. Start mcp server in Namespace or All mode.
2. Open GitHub Copilot in VS Code and switch to Agent mode.
3. Click Refresh on the tools list, and select the MCP Server: Azure MCP.
4. Enter the test prompt List all Event Hubs namespaces in my subscriptions.

Environment:

• OS: Windows.
• Vscode Version: 1.122.1
• Large Language Model: Claude Sonnet 4.6
• Azure MCP Server: 3.0.15

Expected Behavior:
These prompts can successfully trigger the expected mcp tool.

@RickWinter and @g2vinay for notification