Isaac Sim MCP Server

by whats2000

Overview Schema Source Related Servers Discussions Admin

list_prims

Inspect Isaac Sim scene hierarchy by listing prims under a path, filtered by type, with recursive mode to find nested prims or verify deletions.

Instructions

List the prims directly under root_path, optionally filtered by type.

One level deep by default, so list_prims("/") names /World and /Environment rather than everything inside them — a robot alone is hundreds of prims. The response echoes recursive so a shallow answer is never mistaken for a complete one.

Pass recursive=True to walk the whole subtree. That is the one you want when checking whether something was really deleted, or when hunting a prim nested under a robot: a Camera at /World/Arm/EyeCam does not appear in a shallow listing of /World.

Args: root_path: Root path to start listing from. prim_type: Filter by prim type (e.g. "Mesh", "Xform"). With recursive=True, non-matching prims are still descended into, so a Camera under an Xform is found. recursive: Walk the entire subtree instead of one level.

Input Schema

TableJSON Schema

Name	Required	Default
`prim_type`	No
`recursive`	No
`root_path`	No	/

Output Schema

TableJSON Schema

Name	Required	Description	Default
`result`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv0.6.1Sep 22, 2026

addedInput schema / properties / recursive

Added value: +{
+  "default": false,
+  "title": "Recursive",
+  "type": "boolean"
+}

First observedv0.1.0Jun 4, 2026

TDQS

A4.6/5.0

Behavior5/5

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

With no annotations, the description carries the burden and delivers: default one-level depth, the response echo of recursive to prevent false confidence, and the nuanced behavior that non-matching prims are still descended into during recursive filtered searches. It is a read-only listing tool and these semantics are clearly disclosed.

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?

The one-sentence summary is front-loaded and the paragraphs build useful context, but the explanation is slightly verbose. All content earns its place, so it remains strong despite being beyond a minimal summary.

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 an output schema exists and no annotations are present, the description covers the important operational semantics: default depth, filtering, recursive behavior, and a use case. Minor gaps such as absolute path expectations or cost warnings for deep recursion are not stated, but the core calling context is complete.

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 explain every parameter; it does. Each arg gets meaningful semantics: root_path is the starting point, prim_type is exemplified with 'Mesh'/'Xform' and its recursive descent behavior, and recursive defines subtree walking.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description opens with a specific verb-resource pair: 'List the prims directly under root_path, optionally filtered by type.' It immediately clarifies the depth scope, distinguishing this from broader scene inspection tools like search_usd and get_scene_info.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It gives explicit situational guidance: recursive=True 'is the one you want when checking whether something was really deleted, or when hunting a prim nested under a robot.' It does not explicitly route to sibling alternatives for other cases, so it misses the full when-versus-alternatives guidance.

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