[BUG] Azure MCP server could not access resource I have only resource level access

### Describe the bug

1. I have access to Azure AI search resource at resource level, not at subscription level. I do not own that sub and have no access to that sub

2. I configure Azure MCP server and install plugin successfully.

3. I then use az login and select a subscription as prompted. I can't select sub mentioned in #1

When entering prompt which trigger MCP plugin, I always get below error saying I do not have access.
Though in python code, I can access resource using DefaultAzureCredential().

Is there way to fix this in MCP route?

✗ Azure AI Search
{ "status": 500, "message": "Error retrieving Search index details: Service request failed.\r\nStatus: 403 (Forbidden)\r\n\r\nHeaders:\r\nTransfer-Encoding:
chunked\r\nStrict-Transport-Security: REDACTED\r\nPreference-Applied: REDACTED\r\nclient-request-id: 7296506a-8dd1-43e8-9da5-07823ecc108d\r\nx-ms-client-request-id:
7296506a-8dd1-43e8-9da5-07823ecc108d\r\nrequest-id: 7296506a-8dd1-43e8-9da5-07823ecc108d\r\nelapsed-time: 30\r\nDate: Thu, 05 Feb 2026 05:33:47 GMT\r\nContent-Language:
REDACTED\r\n. To mitigate this issue, please refer to the troubleshooting guidelines here at https://aka.ms/azmcp/troubleshooting (https://aka.ms/azmcp/troubleshooting)
.", "results": { "message": "Error retrieving Search index details: Service request failed.\r\nStatus: 403 (Forbidden)\r\n\r\nHeaders:\r\nTransfer-Encoding:
chunked\r\nStrict-Transport-Security: REDACTED\r\nPreference-Applied: REDACTED\r\nclient-request-id: 7296506a-8dd1-43e8-9da5-07823ecc108d\r\nx-ms-client-request-id:
7296506a-8dd1-43e8-9da5-07823ecc108d\r\nrequest-id: 7296506a-8dd1-43e8-9da5-07823ecc108d\r\nelapsed-time: 30\r\nDate: Thu, 05 Feb 2026 05:33:47 GMT\r\nContent-Language:
REDACTED\r\n", "type": "Exception" }, "duration": 0 }

### Expected behavior

Have access

### Actual behavior

Always get error

### Reproduction Steps

1. create resource with resource level access only
2. setup MCP
3. az login select sub
4. try to involve MCP
5. get error

### Environment

production global azure. on windows