measure_distanceCalculate the minimum distance between two CAD entities or points and return the distance plus closest points in centimeters for clearance checks.
Measure minimum distance between two entities. Returns the distance and closest points in cm.
| Name | Required | Description | Default |
|---|---|---|---|
| entity_one | Yes | First entity name (body, sketch, or point 'x,y,z') | |
| entity_two | Yes | Second entity name or point |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotations already declare readOnlyHint, idempotentHint, and destructiveHint, covering the safety profile. The description adds useful non-annotation context by specifying that it returns both the distance and closest points, with the unit in cm.
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 with zero waste. The core operation is front-loaded, and the return information follows immediately.
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 measurement tool with fully described parameters and safety annotations, the description is nearly complete. It covers the return shape and unit, though it could clarify the coordinate context of the returned closest points.
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 100%, so both parameters are fully documented in the schema. The description does not add meaning beyond the schema's entity-type guidance, making the baseline 3 appropriate.
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 names a specific operation (measure minimum distance) and target (between two entities), clearly distinguishing it from sibling measurement tools like measure_angle or get_bounding_box. An agent can tell what it does without opening the schema.
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 states what the tool does but gives no guidance on when to use it versus alternatives such as measure_angle, get_bounding_box, or check_interference. There are no preconditions, exclusions, or routing hints.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.