create-toolset

Create Toolset

You are authoring or extending an Unreal Engine toolset: a collection of static, AI-callable functions registered with the ToolsetRegistry and exposed through the MCP server. The goal is to expand the surface of things Claude/the agent can do inside the editor.

Principles

A good toolset is:

Clean: Design the simplest API that can do useful work in the domain. Don't mirror Unreal's existing APIs directly; they're often unnecessarily complex. A good heuristic: would a technical artist understand this without reading the implementation?

Complete: Support CRUD symmetry. If you can set a thing, you should be able to get it. If there's a create, there should be a delete. Getters without setters are fine when mutation isn't possible or useful.

Composable: Use consistent types for the same kinds of operation across the toolset. If get_graph() returns a Graph, then get_graph_nodes() should accept a Graph. Functions should combine naturally to produce more complex results.

DRY: No duplication within a toolset, and no duplication across toolsets. ObjectTools already provides generic UObject property get/set. Don't reimplement it. If functionality lives elsewhere, call it or point to it.

Before You Write

Work through these questions in order before touching any code.

1. Does the functionality already exist? If the editor is running, call list_toolsets via MCP, then describe_toolset on anything relevant. If MCP isn't available, search the codebase for folders named Toolsets and read the C++ headers or Python toolset files there. If the capability is already exposed, there's nothing to do. Tell the user and point them to the right tool.

2. Is the request more general than it sounds? Users often ask for something domain-specific that is actually an instance of a broader pattern. Before looking for a domain toolset, ask whether the capability truly belongs to that domain or whether it applies more widely. For example, a request for "read blueprint asset metadata" sounds like it belongs in BlueprintTools, but metadata applies to all assets, so the right place is AssetTools. Solving it generically is almost always better than solving it narrowly.