XenozMCP

Overview Schema Source Related Servers Discussions Admin

cloud_set_data_store_entry

Set a value in a Roblox data store by providing universe ID, data store name, key, and value. Optionally create only if the key does not exist.

Instructions

Set a value in a data store

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "universeId": "<universeId>",
      "dataStoreName": "<dataStoreName>",
      "key": "<key>",
      "value": "<value>"
    },
    "name": "cloud_set_data_store_entry"
  }
}

Input Schema

Name	Required	Description
`key`	Yes	Entry key
`value`	Yes	Value to set (JSON string)
`universeId`	Yes	Roblox Universe ID
`dataStoreName`	Yes	Data store name
`exclusiveCreate`	No	Only create if key doesn't exist

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Jul 11, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, and the description only states 'set a value', which implies mutation but does not disclose side effects, permissions required, or behavior when the key already exists. The exclusiveCreate parameter hints at conditional creation, but the description omits it.

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 a single sentence with no fluff, achieving conciseness. However, it could be improved by front-loading key behavioral details (e.g., that it can create or update) without increasing length significantly.

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

Completeness2/5

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

Given the tool has 5 parameters, no annotations, and no output schema, the description is too sparse. It does not explain what a data store is, when to use exclusiveCreate, what the return value is, or any prerequisites. Sibling tools like cloud_get_data_store_entry would benefit from cross-referencing.

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?

All 5 parameters have descriptions in the schema (100% coverage), so the description adds no additional meaning. The schema already explains each parameter, but the description could have clarified the role of exclusiveCreate or that value must be a JSON string.

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

Purpose4/5

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

The description clearly states the action ('set') and resource ('data store'), which distinguishes it from 'get' and 'list' tools. However, it does not specify that it covers both create and update operations, nor does it mention the 'exclusiveCreate' parameter that modifies behavior.

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

Usage Guidelines2/5

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

The description provides no guidance on when to use this tool versus its siblings (e.g., when to use exclusiveCreate, or prerequisites like needing the universeId). The agent is left to infer usage from the parameter names.

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