android-mcp-toolkit

Instructions

Implementation Reference

• src/tools/textLengthTool.js:33-62 (handler)

  The main execution logic for the 'estimate-text-length-difference' tool. Computes character lengths of source and translated text, calculates absolute percentage change, checks against configurable tolerance, determines direction of change, and formats a verdict summary with details.

  async params => {
    const sourceLength = measureLength(params.sourceText);
    const translatedLength = measureLength(params.translatedText);
    const delta = translatedLength - sourceLength;
    const percentChange = sourceLength === 0 ? null : (delta / sourceLength) * 100;
    const exceeds =
      percentChange === null ? translatedLength > 0 : Math.abs(percentChange) > params.tolerancePercent;
    const direction = delta === 0 ? 'no change' : delta > 0 ? 'longer' : 'shorter';
  
    const verdict =
      percentChange === null && translatedLength === 0
        ? '✅ Both texts are empty; no length risk.'
        : percentChange === null
          ? '⚠️ Source length is 0; percent change undefined and translated text is present.'
          : exceeds
            ? '⚠️ Length difference exceeds tolerance (layout risk likely).'
            : '✅ Length difference within tolerance.';
  
    const summary = [
      verdict,
      `Source length: ${sourceLength}`,
      `Translated length: ${translatedLength}`,
      percentChange === null
        ? `Change: N/A (source length is 0; direction: ${direction})`
        : `Change: ${percentChange.toFixed(2)}% (${direction})`,
      `Tolerance: ±${params.tolerancePercent}%`
    ].join('\n');
  
    return { content: [{ type: 'text', text: summary }] };
  }

• src/tools/textLengthTool.js:9-18 (schema)

  Zod input schema defining required sourceText and translatedText strings (non-empty), and optional tolerancePercent number (default 30%, range 1-500).

  const lengthDiffInputSchema = z.object({
    sourceText: z.string().min(1).describe('Original text before translation'),
    translatedText: z.string().min(1).describe('Translated text to compare against the original'),
    tolerancePercent: z
      .number()
      .min(1)
      .max(500)
      .default(30)
      .describe('Allowed absolute percent difference between lengths before flagging risk')
  });

• src/tools/textLengthTool.js:24-64 (registration)

  Function to register the 'estimate-text-length-difference' tool on the MCP server, specifying the tool name, title, description, input schema, and handler function.

  function registerTextLengthTool(server) {
    server.registerTool(
      'estimate-text-length-difference',
      {
        title: 'Estimate text length difference',
        description:
          'Compare original and translated text lengths to detect layout risk; configurable tolerancePercent (default 30%).',
        inputSchema: lengthDiffInputSchema
      },
      async params => {
        const sourceLength = measureLength(params.sourceText);
        const translatedLength = measureLength(params.translatedText);
        const delta = translatedLength - sourceLength;
        const percentChange = sourceLength === 0 ? null : (delta / sourceLength) * 100;
        const exceeds =
          percentChange === null ? translatedLength > 0 : Math.abs(percentChange) > params.tolerancePercent;
        const direction = delta === 0 ? 'no change' : delta > 0 ? 'longer' : 'shorter';
  
        const verdict =
          percentChange === null && translatedLength === 0
            ? '✅ Both texts are empty; no length risk.'
            : percentChange === null
              ? '⚠️ Source length is 0; percent change undefined and translated text is present.'
              : exceeds
                ? '⚠️ Length difference exceeds tolerance (layout risk likely).'
                : '✅ Length difference within tolerance.';
  
        const summary = [
          verdict,
          `Source length: ${sourceLength}`,
          `Translated length: ${translatedLength}`,
          percentChange === null
            ? `Change: N/A (source length is 0; direction: ${direction})`
            : `Change: ${percentChange.toFixed(2)}% (${direction})`,
          `Tolerance: ±${params.tolerancePercent}%`
        ].join('\n');
  
        return { content: [{ type: 'text', text: summary }] };
      }
    );
  }

• src/index.js:29-29 (registration)

  Top-level call to register the text length tool on the main MCP server instance.

  registerTextLengthTool(server);

• src/tools/textLengthTool.js:20-22 (helper)

  Utility function to accurately measure text length by converting to array (handles Unicode grapheme clusters properly).

  function measureLength(text) {
    return Array.from(text).length;
  }