Instantiate a packed scene from a res:// path into the open scene as a child, with undoable changes.
Instantiate a packed scene (res://*.tscn) as a child in the open scene (undoable).
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | ||
| scene | Yes | res:// path to a .tscn/.scn | |
| parent | No |
Changes observed during successful MCP inspections.
v1.12.1v1.10.1v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The description adds 'undoable' which is not conveyed by the annotations (readOnlyHint=false, destructiveHint=false). This provides useful behavioral nuance about reversibility. It does not contradict annotations.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single sentence that is front-loaded with the verb and contains no filler. Every word contributes value, making it highly concise and well-structured.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
With three parameters, no output schema, and sparse annotations, the description is too brief. It omits prerequisite details beyond 'open scene', how parent and name are used, and error/edge-case behavior. The tool is under-specified for an agent to use reliably.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is only 33% (only 'scene' is described). The description does not explain the 'name' or 'parent' parameters, and the 'scene' hint in the description largely repeats the schema. It fails to compensate for the low schema coverage.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action (instantiate), the resource (a packed scene with res://*.tscn), and the target (as a child in the open scene). This distinguishes it from siblings like open_scene or create_node.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The phrase 'in the open scene' implies the prerequisite of an open scene, providing clear context. However, it does not explicitly mention alternatives or when not to use this tool, so it stops short of a 5.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.