MCP prompts with only optional arguments cannot be invoked

[Helmi]

Description

MCP prompts that have only optional arguments (all marked as required: false) cannot be invoked through Claude's interface without providing at least one argument. This affects all prompts in the MCP server, making them unusable without workarounds like sending a placeholder value (e.g., ".").

Context

• Project area: mcp-server prompts system
• Complexity: 3/10 - Configuration/compatibility issue
• Related to: MCP SDK integration with Claude Code

Technical Details

All prompt YAML files in mcp-server/src/templates/prompts/ currently define arguments with required: false:

• create_issue.yaml
• create_pr.yaml
• create_commit.yaml
• work_issue.yaml
• refine_pr.yaml
• check_activity.yaml
• create_changelog.yaml
• create_prompt.yaml

The MCP protocol or Claude's handling may have changed to require at least one argument when invoking prompts.

Requirements

1. Investigate if this is a Claude Code limitation or MCP protocol requirement
2. Check Claude Code GitHub issues for similar reports
3. Determine appropriate fix:
   • If Claude Code issue: Report upstream and implement workaround
   • If our implementation: Update prompt definitions to have at least one required argument where appropriate

Implementation Steps

• Search Claude Code (anthropics/claude-code) GitHub for existing issues about MCP prompts with optional arguments
• Test current behavior with different MCP SDK versions
• Review MCP protocol specification for prompt argument requirements
• If needed, update prompt definitions to include required arguments where semantically appropriate
• If Claude Code bug, create upstream issue and document workaround
• Update documentation about prompt argument requirements

Acceptance Criteria

• Prompts can be invoked from Claude interface without placeholder values
• Solution is documented in PROMPT-STYLE-GUIDE.md
• Any upstream issues are tracked and linked

[Helmi]

I've investigated this issue and confirmed it's a bug in Claude Code, not our implementation.

Filed upstream issue: anthropics/claude-code#5597

Summary

• Our MCP server correctly marks arguments as required: false
• Claude Code shows the prompts but won't invoke them without at least one character of input
• This affects all our prompts with only optional arguments

Current Workaround

Users need to type at least one character (like ".") when invoking prompts with only optional arguments.

Next Steps

Waiting for a fix from Anthropic. Once fixed upstream, this issue can be closed without any changes needed on our side.