Skip to main content
Glama

mass_create_entity_config

Create a MassEntity config asset for Unreal Engine, with optional trait seeding, parent config, overwrite, and save controls.

Instructions

Create a MassEntity config asset and optionally seed trait classes.

Args: name: Asset name to create. path: Content Browser folder under /Game. parent_config: Optional parent MassEntity config asset path. traits: Optional MassEntity trait classes, short names or /Script paths. overwrite: Delete an existing asset before creation. save: Save the asset package after creation.

Returns: Structured JSON with asset path, trait list, and config GUID.

KB: see knowledge_base/23_MASS_ENTITY_AND_STATETREE.md#mcp-mass-statetree-and-smartobject-tools Example: mass_create_entity_config(name="EC_CrowdAgent", traits=["MassAssortedFragmentsTrait"])

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
nameYes
pathNo/Game/Mass/EntityConfigs
saveNo
traitsNo
overwriteNo
parent_configNo

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv1.0.0

TDQS

A3.9/5.0
Behavior4/5

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It reveals non-obvious side effects: 'overwrite: Delete an existing asset before creation' and 'save: Save the asset package after creation.' It also states the return shape as 'Structured JSON with asset path, trait list, and config GUID.' It does not cover failure behavior when the asset exists and overwrite is false, but the core side effects are transparent.

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?

The description is well-structured and appropriately sized for a 6-parameter tool. It front-loads a one-sentence summary, then gives an Args block, Returns, KB pointer, and a concrete example. Every section serves a purpose, especially the example showing 'mass_create_entity_config(name="EC_CrowdAgent", traits=["MassAssortedFragmentsTrait"])'.

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

Completeness4/5

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

Given the input schema, output schema, and this detailed description, an agent has nearly everything needed to call the tool correctly. All parameters are semantically covered, the return format is stated, and an example is present. The main gap is the unspecified behavior when an asset already exists and overwrite=false, which is a minor omission.

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

Parameters5/5

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

Schema description coverage is 0%, so the description must compensate. It does so effectively by explaining each parameter: traits accept 'short names or /Script paths', overwrite means deleting an existing asset, path is 'under /Game', and parent_config is an optional path. This adds meaning beyond the bare schema and gives an agent enough to invoke correctly.

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 opens with a specific verb and resource: 'Create a MassEntity config asset and optionally seed trait classes.' This clearly identifies the tool's purpose and distinguishes it semantically from sibling tools like mass_add_trait (which modifies an existing config) and mass_inspect_entity_config (which reads config). However, it does not explicitly name or reference these alternatives, so differentiation is clear but not explicit.

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 explicit guidance on when to use this tool versus alternatives such as mass_add_trait or mass_inspect_entity_config. Usage must be inferred from the verb 'Create' and the parameter list. There are no context cues, exclusions, or conditional recommendations.

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

Deploy Server

Other Tools