If you run several directories, a connection that can reach all of them is a wider grant than the work usually needs. Setting X-Directory-ID at configuration time means an agent working on one site cannot wander into another — the same instinct as DigitalOcean's per-service endpoints, done with a header instead of a hostname.
Directify's endpoint for their directory-building product. Four tools by their documentation, of which one is named: listing the directories you own.
list_directories is the tool named explicitly; the other three are documented as a group. An X-Directory-ID header narrows the connection to a single directory.
A bearer API token with an optional X-Directory-ID header, or OAuth for clients with native remote support.
Paste a URL, then authorize — add the endpoint to your client, then approve the OAuth consent screen