TOOL4LM

Instructions

Implementation Reference

• src/tools/calc.ts:20-33 (handler)

  Core handler function implementing the calculation logic: normalizes expression, evaluates with mathjs, applies precision formatting, returns success/error object.

  export async function calcEval(expr: string, precision?: number) {
    try {
      const norm = normalizeExponent(expr);
      const res = math.evaluate(norm);
      let out = String(res);
      if (typeof res === 'number' && Number.isFinite(res) && typeof precision === 'number') {
        const p = Math.max(0, Math.min(precision, 20));
        out = res.toFixed(p);
      }
      return { ok: true, result: out };
    } catch (e: any) {
      return { ok: false, error: e?.message || 'calc error' };
    }
  }

• src/server.ts:30-30 (schema)

  Zod input schema for calc_eval tool: required string expr, optional integer precision (0-64).

  { expr: z.string(), precision: z.number().int().min(0).max(64).optional() },

• src/server.ts:29-36 (registration)

  MCP server registration of 'calc_eval' tool: defines name, description, schema, options, and thin async handler wrapper around calcEval.

  server.tool('calc_eval', 'Alias of calc.eval',
    { expr: z.string(), precision: z.number().int().min(0).max(64).optional() },
    OPEN,
    async ({ expr, precision }) => {
      const res = await calcEval(expr, precision);
      return { content: [{ type: 'text', text: JSON.stringify(res) }] };
    }
  );

• src/tools/calc.ts:5-18 (helper)

  Helper utility to normalize mathematical expressions, converting ** to ^ and Vietnamese exponent terms (e.g., 'mũ', 'lũy thừa') to ^ for mathjs compatibility.

  function normalizeExponent(s: string): string {
    let t = s;
  
    // Python style
    t = t.replace(/\*\*/g, '^');
  
    // "mũ", "mu" (viết không dấu), "lũy thừa"
    // ví dụ: "5 mũ 10" -> "5 ^ 10"
    t = t.replace(/\s*(m[ũu]|lu[ũu]y\s*thừa)\s*/gi, ' ^ ');
  
    // tuỳ chọn: gom nhiều khoảng trắng
    t = t.replace(/\s+/g, ' ').trim();
    return t;
  }