roll_dice
Simulate dice rolls using standard notation to generate random numbers for games, decisions, or probability testing.
Instructions
Roll the dice with the given notation
Input Schema
TableJSON Schema
| Name | Required | Description | Default |
|---|---|---|---|
| notation | Yes | ||
| num_rolls | No |
Implementation Reference
- server.py:23-27 (handler)The main handler function for the 'roll_dice' tool, decorated with @mcp.tool() for registration in the MCP server. It creates a DiceRoller instance and returns its string representation containing the roll results.@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:4-47 (helper)The DiceRoller class implements the core dice rolling logic: parses notation like '2d20k1', rolls random dice, keeps highest N rolls, supports multiple rolls, and formats output string used by the tool handler.class DiceRoller: def __init__(self, notation, num_rolls=1): self.notation = notation self.num_rolls = num_rolls self.dice_pattern = re.compile(r"(\d+)d(\d+)(k(\d+))?") 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 def roll_multiple(self): """Roll the dice multiple times according to num_rolls""" results = [] for _ in range(self.num_rolls): rolls, kept_rolls = self.roll_dice() results.append({ "rolls": rolls, "kept": kept_rolls, "total": sum(kept_rolls) }) return results 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)
- server.py:10-10 (registration)Import of the DiceRoller helper class used in the roll_dice tool implementation.from dice_roller import DiceRoller