Material Maker MCP

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add_node

Add a node to a Material Maker graph by specifying its type, optional position and parameters; describe the node type first when ports or parameters are unknown.

Instructions

Add one node. Call describe_node_type first when ports or parameters are unknown.

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": {
      "node_type": "<node_type>"
    },
    "name": "add_node"
  }
}

Input Schema

Name	Required	Description	Default
`position`	No
`node_type`	Yes
`parameters`	No
`material_id`	No

Output Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.3.1Sep 29, 2026

TDQS

B3.3/5.0

Behavior3/5

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

Annotations already declare it is a write, non-idempotent, non-destructive, closed-world operation, so the safety profile is covered. The description adds only the node-type dependency hint and nothing about what graph/material the node attaches to or whether a material must be active first.

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?

Two short sentences, front-loaded with the action, and no wasted words. The prerequisite is stated compactly without padding.

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

Completeness3/5

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

An output schema exists so return values need not be explained, and annotations cover the safety profile. The remaining gap is parameter documentation (0% coverage) and the missing link to which material/graph receives the node, which the description should address for a 4-param mutation.

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

Parameters2/5

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

Schema coverage is 0%, so the description must carry the burden for four parameters, but it does not explain node_type, position, material_id, or the parameters object. The only semantic hint is that ports/parameters are node-type-dependent, which is thin against a total coverage gap.

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 and resource ('Add one node'), which distinguishes it from move_node, remove_node, and duplicate_node. It does not explicitly differentiate from add_graph_fragment, but the unit of action (one node) is clear.

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?

Provides a useful conditional prerequisite ('Call describe_node_type first when ports or parameters are unknown'), which is real guidance. However, it names no alternative tool and gives no when-not guidance versus siblings like duplicate_node or add_graph_fragment.

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