🧠 Brains complement: IF an unreal-engine-skills-manager tool (external MCP) exists in this session, call it with {action: "load", skill: "materials-and-shaders"} for UE domain knowledge on this topic — correct APIs, architecture, best practices — and treat it as the rubric for any review / "best practices" question. If no such tool is available (e.g. running under Claude Code or Codex without that MCP), skip this line entirely and proceed with this skill alone — do NOT attempt the call.

Material System Skill

Critical Rules

🚨 Connecting Function Call Inputs: Use Bare Names, Not Display Names

get_expression_pins(mat, expr_id) (MaterialNodeService) returns input pins with display labels including type suffixes like "TextureObject (T2d)", "TextureSize (V3)", "Use High Quality Normals (SB)". Connections are made through the engine MaterialTools.connect_expressions call, and UE's connect API matches against the bare input name only — never pass these display labels as to_input_name:

MT = "editor_toolset.toolsets.material.MaterialTools"
# ❌ WRONG — display label with type suffix; connection fails silently or gets ignored
call_tool(tool_name="connect_expressions", toolset_name=MT,
          arguments={"from_expression": src_id, "from_output_name": "",
                     "to_expression": fn_id, "to_input_name": "TextureObject (T2d)"})