openstack-mcp-server

List domains

list_domains

Read-onlyIdempotent

Lists Keystone identity domains with optional name and project filters, returning up to 100 results; a forbidden response means the required role is missing, not that no domains exist.

Instructions

List Keystone domains. Usually needs more than a project reader role; forbidden means the role is missing, not that the list is empty. Not paged; narrow with filters.

Input Schema

Name	Required	Description
`name`	No
`limit`	No	Maximum items to return (1-100, default 50).
`project_id`	No	Project ID to work in; omit for the default project. Allowed values are listed by get_scope.

Output Schema

Name	Required	Description
`items`	Yes
`limit`	Yes	Maximum number of items requested.
`complete`	Yes	True when no more items exist beyond this page.
`resource`	Yes	Resource type of the items.
`project_id`	Yes	Project whose session produced the list.
`next_marker`	No	Pass as marker to read the next page; null when complete or when the API has no marker paging.
`observed_at`	Yes	UTC time the list was read.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 30, 2026

TDQS

A4/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/idempotent/non-destructive, and the description adds value on top: it discloses an authorization prerequisite ("usually needs more than a project reader role") and clarifies that a forbidden result signals a missing role rather than an empty list, which prevents a costly misreading. The hedged "usually" softens the guarantee, and return-shape details are left to the output schema.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Three short sentences with zero filler, and the identifying purpose is front-loaded ahead of the operational caveats. Every sentence carries distinct information (identity, auth/error semantics, paging).

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Because an output schema exists, return values need no explanation, and the description covers the two things that schema cannot: authorization behavior and the absence of paging. The only shortfall is the unexplained `name` filter, which leaves an agent guessing at match semantics.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 67%: limit and project_id are documented in the schema, but `name` has no description anywhere. The phrase "narrow with filters" hints at filtering but never explains whether name is an exact match, substring, or glob, so the description does not compensate for the one gap that remains.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb+resource ("List Keystone domains"), which is clearly distinct from sibling tools like list_projects or list_servers. It does not explicitly name any sibling, but the resource is unambiguous, so an agent won't confuse it with anything else in the catalog.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It provides real invocation context: the role requirement, how to interpret a forbidden response, and the advice to narrow with filters instead of paging. There are no competing alternatives to disambiguate, but it also gives no explicit 'when not to use' guidance, keeping it at a strong 4 rather than a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.