MCP Tools Reference: iam.googleapis.com

Tool: list_deny_policies

Lists deny policies attached to a Google Cloud project. Organizations and folders are not supported.

Use this tool to discover deny policies enforced at an attachment point.

This tool requires the following parameters:

  • parent (string): The URL-encoded full resource name of the attachment point where the policies are listed. Only projects are supported. The format is policies/URL_ENCODED_ATTACHMENT_POINT/denypolicies (for example, policies/cloudresourcemanager.googleapis.com%2Fprojects%2Fmy-project/denypolicies).

The following parameters are optional:

  • page_size (int32): The maximum number of policies to return.
  • page_token (string): Pagination token from a previous list request.

The tool returns a list of deny policies attached to the specified resource along with an optional next page token.

The following code sample shows how to use curl to call the list_deny_policies MCP tool.

Curl Request 
curl --location 'https://iam.googleapis.com/mcp' \
--header 'content-type: application/json' \
--header 'accept: application/json, text/event-stream' \
--data '{
  "method": "tools/call",
  "params": {
    "name": "list_deny_policies",
    "arguments": {
      // Provide these details according to the MCP tool specification.
    }
  },
  "jsonrpc": "2.0",
  "id": 1
}'

Input Schema

Request message for ListPolicies.

ListPoliciesRequest

JSON representation 
{
  "parent": string,
  "pageSize": integer,
  "pageToken": string
}
Fields
parent

string

Required. The resource that the policy is attached to, along with the kind of policy to list. Format: policies/{attachment_point}/denypolicies

The attachment point is identified by its URL-encoded full resource name, which means that the forward-slash character, /, must be written as %2F. For example, policies/cloudresourcemanager.googleapis.com%2Fprojects%2Fmy-project/denypolicies.

For organizations and folders, use the numeric ID in the full resource name. For projects, you can use the alphanumeric or the numeric ID.
pageSize

integer

The maximum number of policies to return. IAM ignores this value and uses the value 1000.
pageToken

string

A page token received in a ListPoliciesResponse. Provide this token to retrieve the next page.

Output Schema

Response message for ListPolicies.

ListPoliciesResponse

JSON representation 
{
  "policies": [
    {
      object (Policy)
    }
  ],
  "nextPageToken": string
}
Fields
policies[]

object (Policy)

Metadata for the policies that are attached to the resource.
nextPageToken

string

A page token that you can use in a ListPoliciesRequest to retrieve the next page. If this field is omitted, there are no additional pages.

Policy

JSON representation 
{
  "name": string,
  "uid": string,
  "kind": string,
  "displayName": string,
  "annotations": {
    string: string,
    ...
  },
  "etag": string,
  "createTime": string,
  "updateTime": string,
  "deleteTime": string,
  "rules": [
    {
      object (PolicyRule)
    }
  ]
}
Fields
name

string

Immutable. The resource name of the Policy, which must be unique. Format: policies/{attachment_point}/denypolicies/{policy_id}

The attachment point is identified by its URL-encoded full resource name, which means that the forward-slash character, /, must be written as %2F. For example, policies/cloudresourcemanager.googleapis.com%2Fprojects%2Fmy-project/denypolicies/my-deny-policy.

For organizations and folders, use the numeric ID in the full resource name. For projects, requests can use the alphanumeric or the numeric ID. Responses always contain the numeric ID.
uid

string

Immutable. The globally unique ID of the Policy. Assigned automatically when the Policy is created.
kind

string

Output only. The kind of the Policy. Always contains the value DenyPolicy.
displayName

string

A user-specified description of the Policy. This value can be up to 63 characters.
annotations

map (key: string, value: string)

A key-value map to store arbitrary metadata for the Policy. Keys can be up to 63 characters. Values can be up to 255 characters.

An object containing a list of "key": value pairs. Example: { "name": "wrench", "mass": "1.3kg", "count": "3" }.
etag

string

An opaque tag that identifies the current version of the Policy. IAM uses this value to help manage concurrent updates, so they do not cause one update to be overwritten by another.

If this field is present in a CreatePolicyRequest, the value is ignored.
createTime

string (Timestamp format)

Output only. The time when the Policy was created.

Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: "2014-10-02T15:01:23Z", "2014-10-02T15:01:23.045123456Z" or "2014-10-02T15:01:23+05:30".
updateTime

string (Timestamp format)

Output only. The time when the Policy was last updated.

Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: "2014-10-02T15:01:23Z", "2014-10-02T15:01:23.045123456Z" or "2014-10-02T15:01:23+05:30".
deleteTime

string (Timestamp format)

Output only. The time when the Policy was deleted. Empty if the policy is not deleted.

Uses RFC 3339, where generated output will always be Z-normalized and use 0, 3, 6 or 9 fractional digits. Offsets other than "Z" are also accepted. Examples: "2014-10-02T15:01:23Z", "2014-10-02T15:01:23.045123456Z" or "2014-10-02T15:01:23+05:30".
rules[]

object (PolicyRule)

A list of rules that specify the behavior of the Policy. All of the rules should be of the kind specified in the Policy.

AnnotationsEntry

JSON representation 
{
  "key": string,
  "value": string
}
Fields
key

string
value

string

Timestamp

JSON representation 
{
  "seconds": string,
  "nanos": integer
}
Fields
seconds

string (int64 format)

Represents seconds of UTC time since Unix epoch 1970-01-01T00:00:00Z. Must be between -62135596800 and 253402300799 inclusive (which corresponds to 0001-01-01T00:00:00Z to 9999-12-31T23:59:59Z).
nanos

integer

Non-negative fractions of a second at nanosecond resolution. This field is the nanosecond portion of the duration, not an alternative to seconds. Negative second values with fractions must still have non-negative nanos values that count forward in time. Must be between 0 and 999,999,999 inclusive.

PolicyRule

JSON representation 
{
  "description": string,

  // Union field kind can be only one of the following:
  "denyRule": {
    object (DenyRule)
  }
  // End of list of possible types for union field kind.
}
Fields
description

string

A user-specified description of the rule. This value can be up to 256 characters.

Union field kind.

kind can be only one of the following:
denyRule

object (DenyRule)

A rule for a deny policy.

DenyRule

JSON representation 
{
  "deniedPrincipals": [
    string
  ],
  "exceptionPrincipals": [
    string
  ],
  "deniedPermissions": [
    string
  ],
  "exceptionPermissions": [
    string
  ],
  "denialCondition": {
    object (Expr)
  }
}
Fields
deniedPrincipals[]

string

The identities that are prevented from using one or more permissions on Google Cloud resources. This field can contain the following values:

  • principal://goog/subject/{email_id}: A specific Google Account. Includes Gmail, Cloud Identity, and Google Workspace user accounts. For example, principal://goog/subject/alice@example.com.

  • principal://iam.googleapis.com/projects/-/serviceAccounts/{service_account_id}: A Google Cloud service account. For example, principal://iam.googleapis.com/projects/-/serviceAccounts/my-service-account@iam.gserviceaccount.com.

  • principalSet://goog/group/{group_id}: A Google group. For example, principalSet://goog/group/admins@example.com.

  • principalSet://goog/public:all: A special identifier that represents any principal that is on the internet, even if they do not have a Google Account or are not logged in.

  • principalSet://goog/cloudIdentityCustomerId/{customer_id}: All of the principals associated with the specified Google Workspace or Cloud Identity customer ID. For example, principalSet://goog/cloudIdentityCustomerId/C01Abc35.

  • principal://iam.googleapis.com/locations/global/workforcePools/{pool_id}/subject/{subject_attribute_value}: A single identity in a workforce identity pool.

  • principalSet://iam.googleapis.com/locations/global/workforcePools/{pool_id}/group/{group_id}: All workforce identities in a group.

  • principalSet://iam.googleapis.com/locations/global/workforcePools/{pool_id}/attribute.{attribute_name}/{attribute_value}: All workforce identities with a specific attribute value.

  • principalSet://iam.googleapis.com/locations/global/workforcePools/{pool_id}/*: All identities in a workforce identity pool.

  • principal://iam.googleapis.com/projects/{project_number}/locations/global/workloadIdentityPools/{pool_id}/subject/{subject_attribute_value}: A single identity in a workload identity pool.

  • principalSet://iam.googleapis.com/projects/{project_number}/locations/global/workloadIdentityPools/{pool_id}/group/{group_id}: A workload identity pool group.

  • principalSet://iam.googleapis.com/projects/{project_number}/locations/global/workloadIdentityPools/{pool_id}/attribute.{attribute_name}/{attribute_value}: All identities in a workload identity pool with a certain attribute.

  • principalSet://iam.googleapis.com/projects/{project_number}/locations/global/workloadIdentityPools/{pool_id}/*: All identities in a workload identity pool.

  • principalSet://cloudresourcemanager.googleapis.com/[projects|folders|organizations]/{project_number|folder_number|org_number}/type/ServiceAccount: All service accounts grouped under a resource (project, folder, or organization).

  • principalSet://cloudresourcemanager.googleapis.com/[projects|folders|organizations]/{project_number|folder_number|org_number}/type/ServiceAgent: All service agents grouped under a resource (project, folder, or organization).

  • deleted:principal://goog/subject/{email_id}?uid={uid}: A specific Google Account that was deleted recently. For example, deleted:principal://goog/subject/alice@example.com?uid=1234567890. If the Google Account is recovered, this identifier reverts to the standard identifier for a Google Account.

  • deleted:principalSet://goog/group/{group_id}?uid={uid}: A Google group that was deleted recently. For example, deleted:principalSet://goog/group/admins@example.com?uid=1234567890. If the Google group is restored, this identifier reverts to the standard identifier for a Google group.

  • deleted:principal://iam.googleapis.com/projects/-/serviceAccounts/{service_account_id}?uid={uid}: A Google Cloud service account that was deleted recently. For example, deleted:principal://iam.googleapis.com/projects/-/serviceAccounts/my-service-account@iam.gserviceaccount.com?uid=1234567890. If the service account is undeleted, this identifier reverts to the standard identifier for a service account.

  • deleted:principal://iam.googleapis.com/locations/global/workforcePools/{pool_id}/subject/{subject_attribute_value}: Deleted single identity in a workforce identity pool. For example, deleted:principal://iam.googleapis.com/locations/global/workforcePools/my-pool-id/subject/my-subject-attribute-value.
exceptionPrincipals[]

string

The identities that are excluded from the deny rule, even if they are listed in the denied_principals. For example, you could add a Google group to the denied_principals, then exclude specific users who belong to that group.

This field can contain the same values as the denied_principals field, excluding principalSet://goog/public:all, which represents all users on the internet.
deniedPermissions[]

string

The permissions that are explicitly denied by this rule. Each permission uses the format {service_fqdn}/{resource}.{verb}, where {service_fqdn} is the fully qualified domain name for the service. For example, iam.googleapis.com/roles.list.
exceptionPermissions[]

string

Specifies the permissions that this rule excludes from the set of denied permissions given by denied_permissions. If a permission appears in denied_permissions and in exception_permissions then it will not be denied.

The excluded permissions can be specified using the same syntax as denied_permissions.
denialCondition

object (Expr)

The condition that determines whether this deny rule applies to a request. If the condition expression evaluates to true, then the deny rule is applied; otherwise, the deny rule is not applied.

Each deny rule is evaluated independently. If this deny rule does not apply to a request, other deny rules might still apply.

The condition can use CEL functions that evaluate resource tags. Other functions and operators are not supported.

Expr

JSON representation 
{
  "expression": string,
  "title": string,
  "description": string,
  "location": string
}
Fields
expression

string

Textual representation of an expression in Common Expression Language syntax.
title

string

Optional. Title for the expression, i.e. a short string describing its purpose. This can be used e.g. in UIs which allow to enter the expression.
description

string

Optional. Description of the expression. This is a longer text which describes the expression, e.g. when hovered over it in a UI.
location

string

Optional. String indicating the location of the expression for error reporting, e.g. a file name and a position in the file.

Tool Annotations

Tool annotations are sent to MCP clients to describe the basic risk of a given tool. Most clients treat these hints as untrusted, but they can be used to decide when a confirmation prompt might be sent to a user.

Along with the title string, the following boolean hints are defined as follows:

  • readOnlyHint: If true, the tool doesn't modify its environment. Default: false.
  • destructiveHint: If true, then the tool can perform destructive actions. If false, then the tool can only perform additive actions. Default: true.
  • idempotentHint: If true, then calling the tool repeatedly with the same arguments will have no additional effect on its environment. Default: false.
  • openWorldHint: If true, then the tool can interact with an 'open world' of external entities. If false, then the tool can only interact with internal entities. For example, a web search tool would be open world, while a memory tool would not be open world.

Destructive Hint: ❌ | Idempotent Hint: ✅ | Read Only Hint: ✅ | Open World Hint: ❌