cozyvtt-mcp

Saved Roll Create

saved_roll_create

Save a private dice expression macro for your current campaign. Store a named expression without rolling, enabling quick reuse later.

Instructions

Save a private dice-expression macro for the current user and campaign. Use dice_roll to execute an expression; use saved_roll_update to edit an existing macro without creating another. Members manage only their own macros. The server parses expressions and limits each user to 50 per campaign. Creation is serialized only within this process; each accepted call may create another macro. No dice are rolled and no campaign-visible message is sent by this tool. Returns {ok:true,data} on success; tool-body failures return {ok:false,error} with optional diagnostic data. Argument-schema errors are MCP errors.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`name`	Yes	Macro display label, trimmed to 1..60 characters.
`expression`	Yes	Saved dice expression, trimmed to 1..200 characters; upstream parses it without rolling.

Output Schema

TableJSON Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

Addedv0.3.0Sep 20, 2026

TDQS

A4.6/5.0

Behavior5/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

The description goes well beyond the annotations by disclosing that no dice are rolled, no campaign-visible message is sent, the server enforces a 50-per-campaign limit, and creation is not globally serialized. These are important side-effect and concurrency traits not captured by readOnlyHint, idempotentHint, or destructiveHint alone.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is longer than minimal, but each sentence contributes useful context such as alternatives, side-effect behavior, limits, and return shape. It is front-loaded with the core purpose, though the concurrency and MCP-error details could be trimmed without losing essential guidance.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a mutation tool with output schema, the description is complete: it states ownership, limits, side effects, return conventions, and error behavior. An agent has enough information to decide when to call it and what to expect.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema description coverage is 100%, and the schema already documents both parameters with trimming constraints. The description reinforces that the expression is parsed without rolling, but it does not add meaning beyond what the schema provides.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb and resource: 'Save a private dice-expression macro for the current user and campaign.' It also explicitly distinguishes itself from dice_roll and saved_roll_update, making the tool's purpose unambiguous.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines5/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It clearly tells the agent when to use this tool versus alternatives: use dice_roll to execute, use saved_roll_update to edit, and this tool to create. It also clarifies that members manage only their own macros, providing scoping guidance.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.