Skip to main content
Glama
Sign In
Houdini MCP

Houdini MCP

by beatreichenbach
OverviewSchemaSourceRelated ServersDiscussionsAdmin
Python
Local

list_materials

List all material nodes under a specified root path to inspect and browse the materials available in a Houdini scene.

Instructions

List all material nodes under a root path.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_materials"
  }
}

Input Schema

NameRequiredDescriptionDefault
root_pathNo/mat

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observedv0.1.0

TDQS

C2.8/5.0
Behavior2/5

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

No annotations are supplied, so the description carries the full behavioral burden and does not meet it. It does not state whether the traversal is recursive or one level deep, whether it is a read-only operation, what happens when root_path does not exist, or what the returned entries look like.

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

Conciseness4/5

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

One short sentence with no filler and the scope stated after the action, which reads cleanly. It is arguably too terse for the information an agent needs, but there is no wasted wording.

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?

The tool is simple: one optional parameter, no output schema, no nested objects, so less disclosure is required. Still, the missing recursion semantics and absent read-only signal leave meaningful ambiguity for an agent deciding how to call it and interpret results.

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 description coverage is 0%, and the description only echoes the parameter as 'a root path' without explaining format, the '/mat' default, or whether the default means all materials in the scene. The subtree scoping is a small hint but leaves the single parameter largely undocumented.

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 gives a specific verb and resource ('List all material nodes') plus a scoping condition ('under a root path'), so the operation is immediately understood. It does not distinguish itself from nearby siblings such as get_usd_materials or list_material_types, which appear to overlap in subject matter.

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?

There is no guidance on when to choose this tool over get_usd_materials or list_material_types, nor any stated preconditions. The only implied usage is 'you have a root path and want materials under it', which the agent must infer.

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