mcp-tool-implementation

MCP Tool Implementation Guidelines

When implementing new MCP tools, follow these consistent patterns to maintain code quality and readability:

File Structure

• Place all MCP tool implementations in the src/tools/ directory
• Use kebab-case for filenames (e.g., get-projects.ts, update-flag.ts)
• Name files according to their primary function

Implementation Pattern

1. Import any necessary Unleash API integration functions:

import { requiredFunction } from '../unleash/required-function.js';

1. Create a handler function with the naming convention handle[ToolName]:

async function handle[ToolName](mdc:parameters?: any) {
  try {
    const result = await requiredFunction(parameters);
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(result, null, 2),
        },
      ],
    };
  } catch (error: any) {
    return {
      content: [
        {
          type: 'text',
          text: JSON.stringify(
            {
              success: false,
              error: error.message,
            },
            null,
            2
          ),
        },
      ],
      isError: true,
    };
  }
}

1. Export the tool using a consistent structure:

export const toolName = {
  name: 'toolName',
  description: 'toolDescription',
  handler: handle[ToolName],
};

Error Handling

• Always wrap API calls in try/catch blocks
• Return a standardized error response object when errors occur:
  • Include isError: true flag
  • Include meaningful error messages
  • Maintain the consistent content structure

Response Format

• Always return responses in the following format:

{
  content: [
    {
      type: 'text',
      text: string,
    },
    // More content items if needed
  ],
  isError?: boolean, // Include only for error responses
}

Parameter Handling

• Define clear parameter types when needed
• Validate parameters before using them in API calls
• Handle missing parameters gracefully