Azure Assistant MCP

Instructions

Implementation Reference

• src/azure_assistant_mcp/server.py:542-582 (handler)

  Handler for 'list-subscriptions' tool: resolves credentials, enumerates subscriptions via ARM or defaults, prefers MG scope, fetches display names using ARG KQL query (list_subscriptions_kql), formats and returns list.

  if name == "list-subscriptions":
      tenant_name = arguments.get("tenant_name")
      cred, default_subs = AZURE_CONFIG.get_credentials(tenant_name)
      discovered = _enumerate_subscriptions_for_credential(cred)
      mg = AZURE_CONFIG.get_management_group_id(tenant_name)
      subs = discovered or default_subs
      if not subs and not mg:
          return [types.TextContent(type="text", text=(
              "No subscriptions found and no management_group_id configured. Configure management_group_id or ensure the SP has Reader at root."
          ))]
  
      # If we were able to enumerate, we only have IDs. For user-friendly output,
      # run a small ARG query to fetch display names.
      total_count = len(subs)
      scope_line = ""
      try:
          kql = list_subscriptions_kql()
          # If a management group is configured, prefer listing by MG to include all contained subscriptions
          if mg:
              res = execute_kql(cred, None, kql, top=1000, management_groups=[mg])
              scope_line = f"Scope: managementGroup={mg}"
          else:
              res = execute_kql(cred, subs, kql, top=1000)
              scope_line = f"Scope: subscriptions={len(subs)}"
          if res.get("status") == "success" and res.get("results"):
              rows = res["results"]
              lines = [f"- {r.get('name')} ({r.get('subscriptionId')})" for r in rows]
              total_count = len(rows)
          else:
              lines = [f"- {sid}" for sid in subs]
      except Exception:
          lines = [f"- {sid}" for sid in subs]
          scope_line = f"Scope: subscriptions={len(subs)} (fallback)"
  
      body = [
          f"Tenant: {tenant_name or AZURE_CONFIG.get_default_tenant().get('name')}",
          f"Subscriptions: {total_count}",
          scope_line,
          *lines,
      ]
      return [types.TextContent(type="text", text="\n".join(body))]

• src/azure_assistant_mcp/server.py:165-175 (registration)

  Tool registration including name, description, and input schema for 'list-subscriptions'.

  types.Tool(
      name="list-subscriptions",
      description="List subscriptions accessible to the configured service principal for a tenant.",
      inputSchema={
          "type": "object",
          "properties": {
              "tenant_name": {"type": "string", "description": "Optional configured tenant name"}
          },
          "required": [],
      },
  ),

• src/azure_assistant_mcp/server.py:45-59 (helper)

  Helper function to enumerate accessible subscription IDs using Azure SubscriptionClient.

  def _enumerate_subscriptions_for_credential(credential) -> List[str]:
      """Return list of subscription IDs accessible by the given credential.
  
      Falls back to empty list if enumeration fails or dependency is missing.
      """
      try:
          from azure.mgmt.subscription import SubscriptionClient  # type: ignore
      except Exception:
          return []
      try:
          client = SubscriptionClient(credential=credential)
          return [s.subscription_id for s in client.subscriptions.list()]
      except Exception:
          return []

• src/azure_assistant_mcp/queries.py:22-24 (helper)

  Helper function providing the KQL query template for listing subscriptions (loaded from kql/list_subscriptions.kql or .md).

  def list_subscriptions_kql() -> str:
      return _tmpl("list_subscriptions")