Create a new collection in Blender, optionally nest it under a parent and move existing objects into it.
Create a collection, optionally nested under parent and optionally
moving existing objects into it.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| parent | No | ||
| objects | No | ||
| response_format | No | 'markdown' for readable output, 'json' for raw structured data. | json |
Changes observed during successful MCP inspections.
v2.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare a non-read-only, non-idempotent, non-destructive operation, so the description carries less burden. It does add one behavioral fact beyond annotations: the tool can optionally move existing objects into the new collection. However, it does not disclose what happens when a collection with the same name already exists, whether moving removes objects from their previous collections, or what failure modes exist.
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?
The description is a single 18-word sentence with no filler. The core action comes first, and the optional modifiers follow naturally. Every word earns its place.
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 mutation tool with no output schema, the description is lean. It explains the essential parameters but omits observable outcomes: return value, duplicate-name behavior, parent existence expectations, and side effects on moved objects. Given the number of sibling collection-related tools, an agent would need to infer too much to use this confidently.
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 25%, so the description must compensate; it partially does by clarifying `parent` means nesting and `objects` are existing objects to move into the collection. But `name` is left to its label, and behavior around invalid parent or object references is not described. The `response_format` parameter already has its own schema description.
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 states a clear verb ('Create') and resource ('a collection'), and adds two distinguishing behaviors: nesting under `parent` and moving existing objects into the collection. It is specific enough to be separated from `blender_assign_to_collection` by verb alone, though it does not explicitly name any sibling.
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?
No guidance is given about when to choose this tool over alternatives. There is also nothing about prerequisites (e.g., whether the parent collection must already exist) or when a sibling like `blender_assign_to_collection` would be more appropriate. The only implied context is the purpose itself.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.