I want to limit the resource count created(example vm), but my policy is wrong. please help me.

[cmcmmm]

I want to limit the resource count created(example disk or vm), but my policy is wrong. please help me.

my policy as below:
{
"mode": "All",
"parameters": {
"allowedDiskCount": {
"type": "Integer",
"defaultValue": 5
}
},
"policyRule": {
"if": {
"allOf": [
{
"field": "type",
"equals": "Microsoft.Compute/disks"
},
{
"count": {
"field": "Microsoft.Compute/disks[*]"
},
"greater": "[parameters('allowedDiskCount')]"
}
]
},
"then": {
"effect": "deny"
}
}
}