Preferred MCP Instance

What this is

A lightweight preference, not a management system. If a project has more than one MCP connector instance of the same kind installed — for example, several desktop-automation connectors (Windows or macOS), or more than one filesystem connector, commonly set up so parallel Claude conversations don't queue on the same one — this feature gives a way to name which instance this project should default to. That way a conversation doesn't have to guess, and two open conversations working on the same project don't accidentally collide by both reaching for the same instance at once.

This addresses a genuine practical annoyance more than anything grand: multiple simultaneous conversations writing files or driving desktop automation through the same connector instance can jam up mid-task waiting on each other. It does not speed up any single conversation on its own — one conversation issues tool calls one at a time regardless of how many instances exist. The benefit is entirely about avoiding collisions across separate, parallel conversations, and giving each one a stable, named identity in this project's own instructions if several are open at once.

Deliberately very light: this doesn't set up, install, or configure any MCP servers itself, and doesn't attempt liveness checks, capability fingerprinting, or environment detection beyond a one-sentence Cowork guard. It only records a plain-language preference among instances that already exist, and skips entirely if only zero or one instance is visible (there's nothing to prefer between). For actually adding, removing, or configuring MCP server instances — the deeper setup this feature assumes is already done — see Anthropic's own guide: https://support.claude.com/en/articles/10949351-getting-started-with-local-mcp-servers-on-claude-desktop

Assess first

• Note which MCP connectors are currently visible in this session and, where the name doesn't already make it obvious, what kind of capability each one offers (filesystem access, desktop automation, or something else).
• Note whether more than one instance of the same kind is visible.
• Check whether admin\AGENT_INSTRUCTIONS.md already has a ◆ PREFERRED MCP INSTANCE section from a prior install.

Ask, only if needed

• If two or more instances of the same kind are currently visible: mention it, and ask whether the person wants to set a preference now or skip it and set one later.
• If only zero or one instance is visible: nothing to ask — install the capability anyway (so it's ready once more instances exist) and note that there's currently nothing to prefer between.

Write

Add the following into admin\AGENT_INSTRUCTIONS.md:

◆ PREFERRED MCP INSTANCE

Command: "show me the MCPs" -- list the MCP connectors currently visible
in this session, grouped by what each one does (filesystem access,
desktop automation, or other), noting how many instances of each kind
are available.

Command: "prefer [name]" or "set primary MCP to [name]" -- record the
preference below and use that instance for matching tasks going forward
in this project. If it's ever unavailable, say so and ask before falling
back to a different instance -- don't switch silently.

Chat conversations only. If these instructions are also being read by
Cowork or another agentic/orchestrated environment, ignore any
preference below -- parallel sub-agents should not be funneled through
a single instance.

Adding, removing, or configuring MCP server instances themselves is
outside this feature's scope -- see Anthropic's guide:
https://support.claude.com/en/articles/10949351-getting-started-with-local-mcp-servers-on-claude-desktop

Current preference: [none set / name of preferred instance]

Confirm

Confirm: Preferred MCP Instance is set up. Say "show me the MCPs" anytime to see what's currently available, or "prefer [name]" to pin one for this project going forward. If a preference was set during this install, name it back: "This project currently prefers [name] for [kind] tasks."