[BUG][2.1.56] MCP is not working with more than one argument

Preflight Checklist

• [x] I have searched existing issues and this hasn't been reported yet
• [x] This is a single bug report (please file separate reports for different bugs)
• [x] I am using the latest version of Claude Code

What's Wrong?

So MCP server config is not recognized correctly after setup. Here is the sample setup I have in the claude code

  "mcpServers": {
    "playwright": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "@playwright/mcp@latest", 
        "--browser=chrome"
      ],
      "env": {}
    }
  },

After setting up this

% claude mcp list
No MCP servers configured. Use `claude mcp add` to add a server.

Server is not created correctly. However, if you do the followings

% claude mcp get playwright
playwright:
  Scope: User config (available in all your projects)
  Status: ✓ Connected
  Type: stdio
  Command: npx
  Args: @playwright/mcp@latest --browser=chrome
  Environment:

To remove this server, run: claude mcp remove "playwright" -s user

We can find the server is properly setup.

Workaround (only restricted to 1 arg)

This is still working but cannot add more.

  "mcpServers": {
    "playwright": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "@playwright/mcp@latest"
      ],
      "env": {}
    }
  },

What Should Happen?

The list option should work correctly and allowing multiple argument as inputs.

Error Messages/Logs

Steps to Reproduce

Create the mcp setup with extra args, and not works

  "mcpServers": {
    "playwright": {
      "type": "stdio",
      "command": "npx",
      "args": [
        "@playwright/mcp@latest", 
        "--browser=chrome"
      ],
      "env": {}
    }
  },

Claude Model

None

Is this a regression?

Yes, this worked in a previous version

Last Working Version

_No response_

Claude Code Version

2.1.56

Platform

Anthropic API

Operating System

macOS

Terminal/Shell

Terminal.app (macOS)

Additional Information

_No response_