Create many Roblox instances in one call, with one undo step and one roundtrip. Build entire scenes by specifying className, name, parent, and properties for each item.
Create MANY instances in ONE call (one undo step, one roundtrip). Each item: {className, name?, parent?, properties?}. Building a whole room in a single call.
| Name | Required | Description | Default |
|---|---|---|---|
| items | Yes | Array of {className, name?, parent? (default Workspace), properties?} |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the behavioral burden. It usefully discloses atomicity-style traits ('one undo step, one roundtrip'), but says nothing about what happens on partial failure, whether all requested items are returned, or any permission requirements.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
Three tight fragments, front-loaded with the core benefit (MANY in ONE call) before the item shape and the room-building scenario. No wasted wording.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a mutation tool with no annotations and no output schema, the definition covers the input shape and the atomicity benefit but omits the return value (e.g., created instances/IDs) and error semantics on partial failure. Adequate but with clear gaps.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 100% and there is a single parameter, so the schema already documents the item shape. The description merely restates {className, name?, parent?, properties?} without adding format rules, defaults, or constraints beyond the schema, so the baseline 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb and resource (Create ... instances) with the distinguishing scope 'MANY in ONE call', which clearly separates it from the singular create_instance sibling. An agent can select it without opening the schema.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
Implies usage through rationale ('one undo step, one roundtrip') and a concrete scenario ('Building a whole room in a single call'), which guides selection toward bulk work. However, it never explicitly names create_instance as the alternative or states when to prefer it, so the routing guidance is only implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.