When the #[McpTool] attribute is used on an invokable class, the documentation https://github.com/php-mcp/server?tab=readme-ov-file#mcptool states:
When on an invokable class, defaults to the class's short name (e.g., class AdderTool becomes AdderTool).
However, in my case the name "__invoke" is displayed as McpTool name on both Claude Desktop and Heroku MCP Toolkit.