set_projects_base_dir · Xcode MCP: Risk & Policy

WHAT IT DOES

What set_projects_base_dir does on Xcode

AI agents use set_projects_base_dir to create or update resources in Xcode — usually the action step of a workflow, after the agent has gathered context. Every call changes real data in your Xcode environment.

WHY IT NEEDS A POLICY

Why set_projects_base_dir needs a policy

This tool modifies a configuration setting (base directory) but does not delete data or execute code. The operation is reversible—a different directory can be set later. While it could affect subsequent tool operations by changing where project searches occur, the change itself is non-destructive and represents a Write-category action.

From the tool's definition Tool name 'set_projects_base_dir' and description 'Sets the base directory where your Xcode projects are stored' indicate a configuration modification action.

Attacks that exploit this kind of access

Recommended rule Ready

Verdict

set_projects_base_dir Rate-limited

set_projects_base_dir stays usable, but capped — an agent stuck in a loop can't make hundreds of changes a minute. Everything else on the server is denied unless you say otherwise.

View as policy code

policy.json

{
  "version": "1",
  "default": "deny",
  "tools": {
    "set_projects_base_dir": {
      "limits": [
        {
          "counter": "set_projects_base_dir_rate",
          "window": "minute",
          "max": 30,
          "scope": "grant"
        }
      ]
    }
  }
}

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PolicyLayer is an MCP gateway: every tool call is checked against your rule before it reaches Xcode, so you can run agents against it safely.

FAQ

Questions about set_projects_base_dir

What does the set_projects_base_dir tool do? +

Sets the base directory where your Xcode projects are stored. It is categorised as a Write tool in the Xcode MCP Server, which means it can create or modify data. Consider rate limits to prevent runaway writes.

How do I enforce a policy on set_projects_base_dir? +

Register the Xcode MCP server in PolicyLayer and add a rule for set_projects_base_dir: allow, deny, rate-limit, or require approval. Point your MCP client at the PolicyLayer proxy URL and the rule is enforced on every call, before it reaches Xcode. Nothing to install.

What risk level is set_projects_base_dir? +

set_projects_base_dir is a Write tool with medium risk. Write tools should be rate-limited to prevent accidental bulk modifications.

Can I rate-limit set_projects_base_dir? +

Yes. Add a rate_limit block to the set_projects_base_dir rule in your PolicyLayer policy. For example, setting max: 10 and window: 60 limits the tool to 10 calls per minute. Rate limits are tracked per agent session and reset automatically.

How do I block set_projects_base_dir completely? +

Set action: deny in the PolicyLayer policy for set_projects_base_dir. The AI agent will receive a policy violation error and cannot call the tool. You can also include a reason field to explain why the tool is blocked.

What MCP server provides set_projects_base_dir? +

set_projects_base_dir is provided by the Xcode MCP server (xcode-mcp-server). PolicyLayer sits as a proxy in front of this server to enforce policies before tool calls reach the server.