Isaac Sim MCP Server

by whats2000

Overview Schema Source Related Servers Discussions Admin

clear_scene

Remove all prims from the scene to reset for a fresh simulation. Optionally keep physics or environment to avoid reloading delays.

Instructions

Remove all prims from the scene.

Also empties any environment loaded by load_environment, which removes that environment's collision floor along with it — so a later create_physics_scene finds no floor and supplies its own. The stage's defaultLight is always kept — a stage with no light renders black, which looks like a broken camera.

Args: keep_physics: If True, keep physics scene prims. keep_environment: If True, keep the loaded environment. Reloading one costs seconds, so pass this when clearing objects between attempts.

Input Schema

TableJSON Schema

Name	Required	Description	Default
`keep_physics`	No
`keep_environment`	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 / keep_environment

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

First observedv0.1.0Jun 4, 2026

TDQS

A4.7/5.0

Behavior5/5

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

With no annotations, the description carries the full burden, and it delivers: it discloses destructive scope, the side effect on the environment's collision floor, the interaction with create_physics_scene, and the defaultLight retention policy with a clear rationale. This covers exactly the non-obvious behaviors an agent needs to anticipate.

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 description is longer than necessary in places, but every paragraph adds distinct information: core action, environment/physics side effects, lighting rationale, and parameter meanings. The main sentence is front-loaded, and the Args section is clearly structured.

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

Completeness5/5

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

This destructive tool has no annotations, two optional flags, and cross-tool implications with load_environment and create_physics_scene. The description addresses all of these, explains the defaultLight exception, and gives enough context for correct invocation. With an output schema present, no return-value discussion is needed.

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 coverage is 0%, and the schema only provides titles and defaults, so the description must compensate. It explains both keep_physics and keep_environment in plain language and adds a practical cost rationale for keep_environment, which is precisely the semantic value the schema lacks.

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 opening line, 'Remove all prims from the scene,' states a specific verb and resource and clearly distinguishes this from sibling tools like delete_object, which targets individual prims. The description then sharpens scope by explaining interactions with the loaded environment and the always-kept defaultLight.

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?

The description gives practical guidance on when to use keep_environment ('Reloading one costs seconds, so pass this when clearing objects between attempts') and warns about downstream consequences for create_physics_scene. It does not explicitly name alternatives like delete_object for removing a single prim, but the context is clear.

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