2021 Roblox Studio MCP Bridge

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execute_luau

Run Luau code in the 2021 Roblox Studio edit context and return output, letting AI assistants inspect or modify the DataModel programmatically.

Instructions

Executes Luau code in 2021 Roblox Studio edit context and returns output

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": {
      "code": "<code>"
    },
    "name": "execute_luau"
  }
}

Input Schema

Name	Required	Description	Default
`code`	Yes	Luau code to run

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv1.5.6Sep 30, 2026
- changedInput schema / properties / code / description
```
Previous value: -"Luau code to run in Studio"New value: +"Luau code to run"
```
First observedv1.0.0Sep 12, 2026

TDQS

B3.2/5.0

Behavior2/5

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

With no annotations, the description carries the full behavioral burden. It states the execution context and that output is returned, but says nothing about side effects, sandboxing, whether arbitrary code can mutate the scene, or required permissions — a serious gap for an arbitrary-code-execution tool.

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

Conciseness5/5

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

One compact sentence that front-loads the verb and resource and adds only the distinguishing context. No waste.

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?

No output schema, no annotations, and a single opaque code parameter mean the description must fill many gaps. It doesn't describe return shape, error behavior, or safety constraints, leaving an agent under-informed about invoking an arbitrary-code-execution tool.

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?

Single parameter with 100% schema description coverage ('Luau code to run'), so the baseline is 3. The description adds no format, version, or length constraints beyond what the schema already provides.

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?

States a specific verb (Executes), resource (Luau code), and scoping context (2021 Roblox Studio edit context) plus return behavior. An agent can distinguish it from siblings like run_playtest or start_playtest by the 'edit context' qualifier, though it doesn't explicitly name an alternative.

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

Usage Guidelines3/5

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

The phrase 'in 2021 Roblox Studio edit context' implicitly tells the agent this is for edit-time scripting rather than playtesting, which is useful routing context. However, it names no explicit alternatives and gives no when-not-to-use guidance.

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