Create a new 3D creature model or replace its entire specification, applying default values for missing attributes and returning a summary of the result.
Create a model or replace its whole spec. Missing keys get defaults. Returns a summary.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| note | No | ||
| spec | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full behavioral burden. It discloses the destructive replacement behavior, the defaulting behavior for missing keys, and the return summary. It does not mention permissions or irreversibility, but the core behavioral traits are present.
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 deliver the primary action, the critical defaulting behavior, and the return type. There is no filler, and the main semantic is front-loaded.
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 three-parameter tool with no output schema, the description covers the essential invocation semantics: create/replace, defaults, and summary return. It is slightly thin on explicit sibling differentiation and spec structure, but an agent can reasonably invoke the tool based on the provided information.
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%, so the description must compensate. It adds meaningful semantics for the spec parameter ('Missing keys get defaults') and clarifies replace semantics, but it does not explain the shape of spec or add detail for the name and note parameters beyond what is obvious from their names.
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 uses a specific verb-resource pair ('Create a model or replace its whole spec') and clearly communicates upsert semantics. The phrase 'whole spec' distinguishes it from a partial-update sibling like edit_model.
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 description clearly implies when to use this tool: when creating a model or fully replacing its spec, especially since missing keys get defaults. However, it does not explicitly name edit_model or state when not to use this tool, leaving some routing inference to the agent.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.