Merge multiple mesh objects into a single object, combining their geometry into the first selected object.
Join several mesh objects into the first one, merging their geometry.
| Name | Required | Description | Default |
|---|---|---|---|
| objects | Yes | ||
| 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 indicate this is not read-only, not idempotent, and not destructive (according to the hints). The description adds little beyond the core action: it doesn't state that the source objects are removed or that the first object is permanently modified, nor does it mention any side effects or requirements. With annotations providing only basic flags, the description carries a heavier burden and falls short.
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, clear sentence that is front-loaded with the action and result. No wasted words, and the key information (joining into the first object) is immediately presented.
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?
There is no output schema, and the tool is a mutation with side effects. The description does not mention what happens to the other objects, whether they are deleted, or how the operation is confirmed. It also doesn't specify error handling or requirements (e.g., all objects must be meshes). For an agent to call this correctly, it needs more context about the side effects and how objects are identified.
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?
The schema has 50% coverage; only 'response_format' has a description. The tool description implies that the first element of the 'objects' array is the target, which adds meaning beyond the bare parameter name. However, it doesn't specify that these are object names or how they are referenced, nor does it explain any constraints on the array (e.g., at least two objects). Thus it partially compensates for the schema gap but not fully.
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 specific verb ('Join'), a clear resource ('several mesh objects into the first one'), and the outcome ('merging their geometry'). This distinguishes it from sibling tools like delete, duplicate, or parent objects, and an agent can immediately grasp the operation.
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 explicit guidance on when to use this tool versus alternatives. It doesn't mention prerequisites (e.g., objects must be meshes), what happens to the non-target objects, or any conditions for selection. The context is implied by the purpose but no alternatives or exclusions are stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.