[Bug] MCP Prompt Server doesn't receive extra arguments from cli

[not94]

Description

I just ran a simple mcp server from local and install it on opencode.

Here is my mcp code:

from mcp.server.fastmcp import FastMCP

# Create an MCP server
mcp = FastMCP("Demo")


# Add an addition tool
@mcp.tool()
def add(a: int, b: int) -> int:
    """Add two numbers"""
    return a + b


# Add a dynamic greeting resource
@mcp.resource("greeting://{name}")
def get_greeting(name: str) -> str:
    """Get a personalized greeting"""
    return f"Hello, {name}!"


# Add a prompt
@mcp.prompt()
def greet_user(name: str, style: str) -> str:
    """Generate a greeting prompt"""
    styles = {
        "friendly": "Please write a warm, friendly greeting",
        "formal": "Please write a formal, professional greeting",
        "casual": "Please write a casual, relaxed greeting",
    }

    return f"{styles.get(style, styles['friendly'])} for someone named {name}."

But when I pass multiple arguments into command line, the server just receive name argument but not style argument:

# local_test is my mcp server name
/local_test:greet_user 123 formal

Please write a warm, friendly greeting for someone named 123 formal.

I have checked mcp prompt implementation #5767, but didn't find any issues.

Plugins

No response

OpenCode version

1.1.20

Steps to reproduce

See the description.

Screenshot and/or share link

No response

Operating System

No response

Terminal

ITerm2

[github-actions]

This issue might be a duplicate of existing issues or related to known argument parsing problems. Please check:

• [FEATURE]: Slash command accepts arguments #3272: Slash command accepts arguments - Feature request for argument passing in commands/prompts
• Named arguments for command parsed from $ARGUMENTS #2226: Named arguments for command parsed from $ARGUMENTS - Explores better argument handling for commands
• **/editor command fails when VISUAL contains arguments with spaces/quotes** #7749: /editor command fails when VISUAL contains arguments with spaces/quotes - Similar issue with argument parsing

The root cause appears to be related to how command-line arguments are parsed and passed to MCP prompts. Feel free to ignore if your specific case is different from these issues.

[jbeers]

I have a similar issue using both 1.1.28 and 1.1.32.

I am not getting back any arguments though. I'm getting back their literal placeholders.

{
    "method": "prompts/get",
    "params": {
        "name": "tellJoke",
        "arguments": {
            "cats": "$1"
        }
    },
    "jsonrpc": "2.0",
    "id": 5
}

[github-actions]

To stay organized issues are automatically closed after 90 days of no activity. If the issue is still relevant please open a new one.