[BUG] If subscription_list tool called, copilot only uses first response instead of user prompting or other defaults

[mattscheffer]

Describe the bug

I'm not 100% that this isue is the Azure MCP or copilot in general.
I'm seeing frequent cases where copilot does not know what subscription is needed and looks for it via the Azure MCP subscription_list tool. This returns a list of subscriptions correctly. At this point Copilot will typically pick the first subscription which might be quite often incorrect.

Expected behavior

If a subscription needed is unknown, it should do one of the following:

• Determine if there is a default subscription somewhere.
  • Could use get_auth_context from GithubCopilotForAzure extension to see which subscriptions are selected. (Doesn't usually do this)
  • Run az cli command to determine with subscription is default there.
• Ask for user input after grabbing the list of subscriptions.

Actual behavior

Copilot gets the list of subscriptions from the tool subscription_list. It picks the first one and continues the prompt using that subscription. The first subscription often changes. I've seen it be 4 different subscriptions out of my ~50.

Occasionally at the end of the prompt it will ask if the user wants to check other subscriptions, but this is infrequent, especially if the prompt finds results.

Reproduction Steps

In a new conversation type a prompt to search for a resource type. Such as:

• List all container apps in my subscription:
• Show me my regis resources.

GithubCopilotForAzure-Testing can be enabled or disabled. It will occasionally use ARG to search if enabled instead.

Environment

VSCode Stable 1.105.1
MCP Server 20251104.1
Windows 11

[joshfree]

MCP Server 20251104.1
Thanks for reaching out @mattscheffer -- could you clarify which version of Azure MCP Server you're using?

@ArthurMa1978 could you assist please?