mcp-devtools / rules

---
description: MCP Tool Implementation Guidelines
globs: packages/*/src/tools/*.ts
alwaysApply: true
---

# MCP Tool Implementation Guidelines

When implementing a new MCP tool, follow these patterns:

@file packages/jira/src/tools/getTicket.ts
@file .cursor/rules/typescript-style.mdc

## Tool Registration

```typescript
export const registerToolName = (server: McpServer): void => {
  const toolParams = {
    // Define parameters according to JSON schema
  };

  // For tools with aliases, use an array of tool names
  const toolNames = ["primary_tool_name", "alias_1", "alias_2"];

  // Register all tool names with the same handler
  for (const tool of toolNames) {
    server.tool(tool, toolParams, async (params) => {
      try {
        // Implementation
        return {
          message: "Success message",
        };
      } catch (error) {
        return {
          error: `Error message: ${error.message}`,
        };
      }
    });
  }
};
```

## Parameter Validation

- Always validate required parameters early in the function
- Use TypeScript types/interfaces for parameter typing
- Document parameters with clear descriptions

## Error Handling

- Use try/catch blocks for all API calls
- Return meaningful error messages
- Log errors with appropriate context

## Documentation

- Update the README.md with your new tool
- Add the tool to the Tool Reference table with all parameters
- Include any aliases in the documentation