Narrowing a big server to the tools one streamline needs, what happens when a server adds tools, and why a tool can disappear for you
Some servers offer a whole system: dozens of tools for every part of a business. A streamline does one job, so it should see only the tools that job needs.
Allow: only these tools
Open the streamline in the Library, find the server under MCP servers, and open its Tools. Under Allow, add the tools this streamline may use. A * stands for any characters, so account_* covers every tool whose name starts with account_.
With Allow set, any other tool on the server doesn't exist for this streamline: the assistant isn't told about it, and a call to it is refused. Hidden still takes tools out of what Allow lets in, and the other rules decide which allowed tools ask first. Without Allow, every tool the server offers is available, as before.
The Concierge suggests an Allow list when a server has many tools. You see the change and save it with a tap.
When a server's tools change
Servers add, rename and remove tools. When that happens, the streamline's page in the Library shows Tools changed on the server: which new tools are now available, which are left out, and which tools your rules name are gone. The next chat in that streamline says so once too. Tap Review to open the server's tool rules, or Dismiss.
In an organization, owners and admins see this notice in the Library; members never do. An admin can Leave It Out (the tool is denied) or Add It (the tool is named, and asks before it runs until someone changes that). Both are staged like any other change and go live when published.
When a tool isn't available to you
The system behind a server decides what each person may do. If it refuses a step because you aren't allowed, you see what it said, and the assistant stops offering that step to you: it is told this isn't available to you. The tool comes back when you sign in to that system again, when the streamline changes, or after a day.
A step that failed because the system was down or busy is never hidden.
In an organization, owners and admins see refused steps on the Usage page under Refusals, so they can change the streamline or your permissions in that system. See What is sent, and what never is (PR-2).
The same manual ships inside the app. This section as Markdown