Tavily Web Search MCP Server

Instructions

Implementation Reference

• server.py:19-24 (handler)

  The MCP tool handler for 'roll_dice', decorated with @mcp.tool(), which instantiates DiceRoller with parameters and returns its formatted string result.

  @mcp.tool()
  def roll_dice(notation: str, num_rolls: int = 1) -> str:
      """Roll the dice with the given notation"""
      roller = DiceRoller(notation, num_rolls)
      return str(roller)

• dice_roller.py:10-23 (helper)

  Core helper method in DiceRoller class that parses dice notation (e.g., 2d20k1), rolls the dice, sorts descending, keeps highest N, and returns all rolls and kept rolls.

  def roll_dice(self):
      match = self.dice_pattern.match(self.notation)
      if not match:
          raise ValueError("Invalid dice notation")
  
      num_dice = int(match.group(1))
      dice_sides = int(match.group(2))
      keep = int(match.group(4)) if match.group(4) else num_dice
  
      rolls = [random.randint(1, dice_sides) for _ in range(num_dice)]
      rolls.sort(reverse=True)
      kept_rolls = rolls[:keep]
  
      return rolls, kept_rolls

• dice_roller.py:37-47 (helper)

  Helper method that performs the actual rolling (single or multiple) and formats the output string consumed by the tool handler.

  def __str__(self):
      if self.num_rolls == 1:
          rolls, kept_rolls = self.roll_dice()
          return f"ROLLS: {', '.join(map(str, rolls))} -> RETURNS: {sum(kept_rolls)}"
      else:
          results = self.roll_multiple()
          result_strs = []
          for i, result in enumerate(results, 1):
              result_strs.append(f"Roll {i}: ROLLS: {', '.join(map(str, result['rolls']))} -> RETURNS: {result['total']}")
          return "\n".join(result_strs)