vm-count-by-tenant

Count virtual machines across Azure tenants and subscriptions using Azure Resource Graph queries to track VM inventory in multi-tenant environments.

Instructions

Count virtual machines per configured tenant (uses all subscriptions when available).

Input Schema

TableJSON Schema

Name	Required	Description	Default
`tenant_names`	No	Optional subset of tenant names to include
`use_all_subscriptions`	No	Try to include all subscriptions in each tenant (fallbacks to default)

Implementation Reference

src/azure_assistant_mcp/server.py:493-540 (handler)

Handler logic for the 'vm-count-by-tenant' tool within the call_tool function. Loops over tenants, scopes subscriptions or management group, executes vm_count_kql query, aggregates and formats VM counts.

if name == "vm-count-by-tenant":
    # Optional: restrict to certain tenants
    wanted = set(arguments.get("tenant_names", []) or [])
    try_all = bool(arguments.get("use_all_subscriptions", True))

    tenants = AZURE_CONFIG.get_tenants()
    if wanted:
        tenants = [t for t in tenants if t.get("name") in wanted]
        if not tenants:
            return [types.TextContent(type="text", text="No matching tenants found.")]

    rows: List[str] = []
    total = 0
    for t in tenants:
        tname = t.get("name") or t.get("id")
        cred, default_subs = AZURE_CONFIG.get_credentials(tname)
        mg = AZURE_CONFIG.get_management_group_id(tname)
        subs = list(default_subs)
        if try_all and mg:
            subs = []  # force MG usage below
        elif try_all:
            discovered = _enumerate_subscriptions_for_credential(cred)
            if discovered:
                subs = discovered

        if not subs:
            rows.append(f"- {tname}: 0 (no subscriptions)")
            continue

        kql = vm_count_kql()
        if try_all and mg and not subs:
            result = execute_kql(cred, None, kql, top=1, management_groups=[mg])
        else:
            result = execute_kql(cred, subs, kql, top=1)
        if result["status"] != "success" or not result.get("results"):
            rows.append(f"- {tname}: error ({result.get('error','query failed')})")
            continue
        count = int(result["results"][0].get("VMCount", 0))
        total += count
        rows.append(f"- {tname}: {count}")

    body = [
        "VM counts by tenant:",
        *rows,
        "",
        f"Total VMs across tenants: {total}",
    ]
    return [types.TextContent(type="text", text="\n".join(body))]

src/azure_assistant_mcp/server.py:153-164 (registration)

Tool registration in @server.list_tools() decorator, defining name, description, and input schema for 'vm-count-by-tenant'.

types.Tool(
    name="vm-count-by-tenant",
    description="Count virtual machines per configured tenant (uses all subscriptions when available).",
    inputSchema={
        "type": "object",
        "properties": {
            "tenant_names": {"type": "array", "items": {"type": "string"}, "description": "Optional subset of tenant names to include"},
            "use_all_subscriptions": {"type": "boolean", "description": "Try to include all subscriptions in each tenant (fallbacks to default)", "default": True}
        },
        "required": [],
    },
),

src/azure_assistant_mcp/server.py:156-162 (schema)

Input schema definition for the 'vm-count-by-tenant' tool, specifying optional tenant_names array and use_all_subscriptions boolean.

inputSchema={
    "type": "object",
    "properties": {
        "tenant_names": {"type": "array", "items": {"type": "string"}, "description": "Optional subset of tenant names to include"},
        "use_all_subscriptions": {"type": "boolean", "description": "Try to include all subscriptions in each tenant (fallbacks to default)", "default": True}
    },
    "required": [],

src/azure_assistant_mcp/queries.py:39-40 (helper)
Helper function that loads and returns the KQL template for counting virtual machines (via kql_loader.load_kql_template('vm_count')).
```
def vm_count_kql() -> str:
    return _tmpl("vm_count")
```

Azure Assistant MCP