[BUG] "Error: unknown option '-y'" when adding mcp with npx in native windows installation

Environment

• Platform (select one):
• [ x ] Anthropic API
• Claude CLI version: 1.0.53 (Claude Code)
• Operating System: Windows 10 Pro 22H2
• Terminal: PowerShell

Bug Description

Trying to add mcp servers that work through npx locally, for example
claude mcp add context7 -- npx -y @upstash/context7-mcp
Result: error: unknown option '-y received, no server added

Tried reinstalling CC, rebooting terminal and PC, nothing works
Not sure if it's the problem in Claude Code or somewhere else

Steps to Reproduce

1. CC installed natively on Windows
2. run claude mcp add context7 -- npx -y @upstash/context7-mcp in PowerShell

Expected Behavior

MCP server added successfully

Actual Behavior

error: unknown option '-y received, no server added

Additional Context

It seems HTTP and SSE transport work fine