What an MCP client can do
The tools an MCP client can use, which ones are sensitive, and the rules every client follows.
An MCP client can use the same kinds of tools as the Workspace Assistant, plus a few for your workspaces and your account. You choose which tools each client may use on its page under Settings, MCP clients. See Manage MCP clients.
Rules every client follows
- It acts as you. A client can only reach what you can reach yourself.
- It works in one workspace at a time. Each request names a workspace. The client finds your workspaces with List workspaces. If it asks for a workspace it cannot reach, the request is refused with a list of the workspaces it can reach.
- AI switches apply. A client cannot reach a workspace with AI off, or a mailbox, calendar or drive with AI off. See How AI works in Metis Suite.
- Hidden workspaces are out of reach. A workspace you turned off for this client cannot be used.
- There is no approval card. A sensitive tool works only after you turn it on for that client. Once it is on, the client can use it without asking you.
- Some actions follow workspace roles. For example, only workspace owners and admins can delete workflows or remove members, whether they use a client or not.
- It cannot change its own access. No tool changes your AI switches, sharing or any client’s settings.
- Requests are limited. If a client sends too many requests in a minute, it is told to wait and try again.
Non-sensitive tools
These are on for a new client. They read and organize your mail, calendars and drives.
| Group | What the client can do |
|---|---|
| Workspaces | List your workspaces, and open one to see what is in it |
| Account | List your connected accounts, see which accounts are unavailable, and list your sign-up invitations |
| Mailboxes | List mailboxes |
| Messages | See a combined inbox, list emails, read an email or a whole conversation, read the original source, list and read attachments, summarize a conversation, search contacts, and check an email for phishing (when phishing detection is on) |
| Search | Search mail |
| Actions | Mark as read or unread, star, archive and restore emails |
| Labels | List labels, set or clear labels, and create a label |
| Drafts | Create and update drafts |
| Snooze & schedule | Snooze, unsnooze and cancel a snooze, list snoozed emails, and list scheduled emails |
| Triage | Mute and unmute conversations, use Read later, and find newsletters |
| Workflows | List workflows and runs, open a run, and try an Ask step on recent mail (when your server offers Ask and Branch steps) |
| Calendar | List calendars and events, and read an event with attendee responses |
| People | List members and their roles, and find mail, events and files linked to a member |
| Drive | List drives, browse folders, search files, read file details and text files, see storage use, and pin or unpin folders |
| Workspace admin | List pending workspace invitations (owners and admins only) |
Sensitive tools
These are off for a new client. Turn on only the ones you need.
| Group | Tools |
|---|---|
| Workspaces | Create workspace, Attach to workspace |
| Account | Send sign-up invite, Revoke sign-up invite |
| Actions | Delete emails, Send email |
| Labels | Delete label |
| Drafts | Delete draft |
| Snooze & schedule | Schedule email, Cancel scheduled, Retry scheduled |
| Triage | Unsubscribe |
| Workflows | Create workflow, Update workflow, Toggle workflow, Delete workflow, Run workflow now, Cancel workflow run, Retry workflow run |
| Calendar | Create event, Update event, Delete event, Respond to invite |
| Drive | Create folder, Rename file, Move file, Delete file |
| Workspace admin | Revoke invite, Remove member, Change accent color |
When a client creates, changes or deletes an event, or responds to an invitation, the attendees are notified. A client can move files only within the same drive.
Tools for the server owner
If you are the owner of your Metis Suite server, your clients also see tools in the Instance (owner) and System (owner) groups. They give read-only views of the server, such as totals, AI usage, people, workspaces, settings and warnings. Secret settings are only reported as set or not set. Run health check is a sensitive tool. Other people never see these tools.
What a client can never do
Like the in-app assistants, an MCP client cannot upload files, create share links, change AI switches, calendar visibility, drive folders or sharing, change member roles, send workspace invitations, or do anything that needs your two-factor code. See What the assistant can do.