[BUG] non-interactive mcp add doesn't accept arguments

Environment

• Platform (select one):
• [ ] Anthropic API
• [x] AWS Bedrock
• [ ] Google Vertex AI
• Claude CLI version: 0.2.53 (Claude Code)
• Operating System: macOS 15.3.2 (24D81)
• Terminal: iTerm2

Bug Description

Using mcp-server-fetch as an example (can be any python module mcp, runnable as python -m module_name_mcp), there is no obvious way to connect it to claude code in non-interactive way (without using the wizard).

What I tried:

1.

claude mcp add fetch python '-m mcp_server_fetch'
error: unknown option '-m mcp_server_fetch'

2.

claude mcp add fetch python -m mcp_server_fetch
error: unknown option '-m'

3.

claude mcp add fetch 'python -m mcp_server_fetch'
Added stdio MCP server fetch with command: python -m mcp_server_fetch  to local config

claude --mcp-debug
MCP server "fetch" Connection failed: spawn python -m mcp_server_fetch ENOENT

1. Using wizard works:

claude mcp add
1. Server Name: fetch
2. Server Scope: project
3. Server Command: python -m mcp_server_fetch

claude
> /mcp
  ⎿  MCP Server Status

     • fetch: connected

Steps to Reproduce

1. pip install mcp-server-fetch
2. claude mcp add --scope project fetch "python -m mcp_server_fetch"

Expected Behavior

added mcp server works

.mcp.json produced:

{
  "mcpServers": {
    "fetch": {
      "type": "stdio",
      "command": "python",
      "args": ["-m",  "mcp_server_fetch"],
      "env": {}
    }
  }
}

Actual Behavior

added mcp server fails to spawn

.mcp.json produced:

{
  "mcpServers": {
    "fetch": {
      "type": "stdio",
      "command": "python -m mcp_server_fetch",
      "args": [],
      "env": {}
    }
  }
}

Additional Context

Looks like the issue is in how mcp add parses arguments and could be related to #526.