Retrieve the current unit system of an active Rhino document. Check whether the document uses millimeters, meters, inches, or other units before modeling or exporting.
Read the current document unit system.
| Name | Required | Description | Default |
|---|---|---|---|
| args | Yes |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The readOnlyHint annotation already establishes that this is a safe read operation, so the description does not need to repeat that. It adds little beyond the annotation, but it does clarify scope ('current document unit system'), and there is no contradiction with the annotation.
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 one short sentence with no filler or repetition. It fronts the key action and resource clearly, which is appropriate for a simple getter tool.
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 simple read-only getter with an output schema and a single optional-looking parameter, the description covers the core operation. The only notable gap is not spelling out that doc_id can target a specific document, but the schema itself documents 'active' and document handles.
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 description provides no meaning for the doc_id parameter, and schema description coverage is reported as 0%. Since there is only one parameter and the description does not compensate by explaining how to target a document or use 'active', the agent gets no help from the description for parameter selection.
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?
Description uses a specific verb ('Read') and a clear resource ('the current document unit system'), distinguishing it from the sibling 'rhino_document_units_set' and 'rhino_set_units'. An agent can immediately tell this is the getter for units, not a mutator.
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 on when to use this tool versus alternatives. It does not mention that it is for querying only, that 'rhino_document_units_set' is the counterpart for modifying units, or any context on when the doc_id parameter should be something other than 'active'.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.