MCP Character Tools

Instructions

Implementation Reference

• src/tools/spelling.ts:215-242 (handler)

  The core handler function implementing the reverse_text tool logic: reverses text character-by-character or word-by-word, detects palindromes, and provides descriptive output.

  export function reverseText(input: ReverseTextInput): ReverseTextOutput {
    const { text, reverse_words_only } = input;
    
    let reversed: string;
    if (reverse_words_only) {
      // Reverse order of words but keep each word's characters in order
      reversed = text.split(/(\s+)/).reverse().join('');
    } else {
      // Reverse all characters
      reversed = [...text].reverse().join('');
    }
  
    const normalizedOriginal = text.toLowerCase().replace(/[^a-z0-9]/g, '');
    const normalizedReversed = [...normalizedOriginal].reverse().join('');
    const is_palindrome = normalizedOriginal === normalizedReversed && normalizedOriginal.length > 0;
  
    const description = reverse_words_only
      ? `Words reversed: "${text}" → "${reversed}"`
      : `Characters reversed: "${text}" → "${reversed}"${is_palindrome ? ' (This is a palindrome!)' : ''}`;
  
    return {
      original: text,
      reversed,
      reverse_words_only,
      is_palindrome,
      description,
    };
  }

• src/tools/spelling.ts:202-213 (schema)

  TypeScript interfaces defining the input (text and reverse_words_only option) and output (reversed text, palindrome check, description) types for the reverseText handler.

  export interface ReverseTextInput {
    text: string;
    reverse_words_only: boolean;
  }
  
  export interface ReverseTextOutput {
    original: string;
    reversed: string;
    reverse_words_only: boolean;
    is_palindrome: boolean;
    description: string;
  }

• src/index.ts:341-371 (registration)

  MCP server registration of the 'reverse_text' tool, including Zod input schema validation, description, annotations, and wrapper calling the reverseText handler.

  server.registerTool(
    "reverse_text",
    {
      title: "Reverse Text",
      description: `Reverse text character-by-character or word-by-word.
  
  Also detects if the text is a palindrome.
  
  Args:
    - text (string): The text to reverse
    - reverse_words_only (boolean): Reverse word order only, not characters (default: false)
  
  Returns: Reversed text, palindrome detection.
  
  Example: reverse_text("hello") → "olleh"; reverse_text("racecar") → "racecar" (palindrome!)`,
      inputSchema: z.object({
        text: z.string().min(1).describe("The text to reverse"),
        reverse_words_only: z.boolean().default(false).describe("Reverse word order only"),
      }).strict(),
      annotations: { readOnlyHint: true, destructiveHint: false, idempotentHint: true, openWorldHint: false },
    },
    async (params) => {
      const result = reverseText({
        text: params.text,
        reverse_words_only: params.reverse_words_only,
      });
      return {
        content: [{ type: "text" as const, text: result.description }],
      };
    }
  );

• src/index.ts:356-359 (schema)

  Zod runtime input schema for the reverse_text tool registration, validating text (non-empty string) and reverse_words_only (boolean, default false).

  inputSchema: z.object({
    text: z.string().min(1).describe("The text to reverse"),
    reverse_words_only: z.boolean().default(false).describe("Reverse word order only"),
  }).strict(),