Instantiates a local component and applies supported properties like position, size, fill, and layout. Requires an existing component built with create_node or create_scene first.
Create an instance of a local component and apply supported properties. Build components with create_node or create_scene first.
| Name | Required | Description | Default |
|---|---|---|---|
| props | No | ||
| parentId | No | ||
| componentId | Yes |
Changes observed during successful MCP inspections.
v0.6.4Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare this is a non-read-only, destructive, closed-world write, so the safety profile is covered. The description adds the sequencing constraint and hints that only 'supported' properties are applied, but never says what gets mutated, what happens to unsupported props, or what is returned. Adequate but thin for a destructive mutation.
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?
Two short sentences, front-loaded with the action and followed by the precondition. Every sentence earns its place with no filler.
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?
For a tool with a 3-parameter schema, one of which is a deeply nested properties object, no output schema, and a destructive write annotation, this description is under-specified. It omits what the returned instance identifier is, whether props are optional, and how the large supported-property surface is scoped.
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 0% and the schema defines a large nested 'props' object (~30 fields) with no per-field descriptions, so the description carries the burden. It only says 'apply supported properties' without naming or scoping any of them, adding essentially no meaning beyond the schema's own constraints.
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?
States a specific verb+resource ('Create an instance of a local component') and adds the precondition that a component must already exist, which separates it from create_node/create_scene. It doesn't fully clarify how an instance differs from a plain node or scene, but the purpose is unambiguous.
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 second sentence gives a real prerequisite ('Build components with create_node or create_scene first'), which is useful ordering guidance. However, it offers no when-not guidance or alternatives for cases where create_node/create_scene might be preferred over instancing, so usage is only partially implied.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.