[Microsoft Foundry Extensions][Namespace] Failed to trigger mcp tools

**Description:**
In `Namespace` mode, testing prompts related to [Microsoft Foundry Extensions](https://github.com/microsoft/mcp/blob/main/servers/Azure.Mcp.Server/docs/e2eTestPrompts.md#microsoft-foundry-extensions) with almost all prompts, mcp tools can hardly to be triggered.

Bot rather call `Microsoft Foundry MCP` or `Azure Resource Manager MCP`. Both tools failed due to authentication issues, even though the Azure CLI was already signed in successfully.

**Steps to Reproduce:**
1. Start mcp server in `Namespace` mode or `All` tools mode.
2. Open GitHub Copilot in VS Code and [switch to Agent mode](https://code.visualstudio.com/docs/copilot/chat/chat-agent-mode).
3. Enter the test prompt.

**Environment:**
- OS: Windows.
- Vscode Version: 1.134
- Large Language Model: **GPT-5.6 Sol**
- Azure MCP Server: **3.0.37**

**Expected Behavior:**
1. The mcp tools could be triggered successfully in namespace mode.
2. `Microsoft Foundry MCP` or `Azure Resource Manager MCP` can run successfully if triggered.

@RickWinter and @g2vinay for notification