Nil values for optional arrays returns error

[A-Georgiou]

Describe the bug

A clear and concise description of what the bug is.

When attempting to use the MCP tools in Claude, experimenting with the create_issue tool, I found that optional arrays are passed in as 'nil'. This is not handled currently by server.go

Example Error:

{
  `body`: `This is a test issue created via Claude to verify GitHub API functionality. Feel free to close it when no longer needed.`,
  `repo`: `SmartDNN`,
  `owner`: `A-Georgiou`,
  `title`: `Test Issue`
}
Error executing code: MCP error -32603: failed to create issue: POST https://api.github.com/repos/A-Georgiou/SmartDNN/issues: 422 Invalid request.

For 'properties/assignees', nil is not an array.
For 'properties/labels', nil is not an array. []

Affected version

Please run docker run -i --rm ghcr.io/github/github-mcp-server ./github-mcp-server --version and paste the output below

server version v0.1.0-rc.1 (87d4407d1c3dd12eacf9f134534f44d016fd363c) 2025-04-03T21:37:05Z

Steps to reproduce the behavior

1. Query the Claude MCP to create a simple test issue on a local repo

Expected vs actual behavior

A clear and concise description of what you expected to happen and what actually happened.

Expected: The MCP tool to create an issue on the respective repo
Actual: The tool call fails and the LLM attempts to recover by repeatedly calling with different parameters

[A-Georgiou]

This issue might have been caused by this change to switch from strings with comma separated lists to using an actual array: #82