measure_distanceCalculate the minimum distance between two entities in Fusion 360—bodies, sketches, or points—by providing their names or coordinates. Use it to validate clearances during product development.
Measure minimum distance between two entities
| 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?
Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, indicating this is a safe, repeatable read operation. The description adds minimal behavioral context beyond this, specifying 'minimum distance' but not detailing output format, units, or error conditions. It doesn't contradict annotations, but adds limited value.
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, efficient sentence that directly states the tool's function without unnecessary words. It's front-loaded with the core purpose and contains zero redundant information, making it easy for an agent to parse quickly.
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?
Given the tool's moderate complexity (distance measurement between entities), the description is minimally adequate. Annotations cover safety and idempotency, and the schema fully documents parameters. However, without an output schema, the description doesn't explain return values (e.g., numeric distance, units), leaving a gap for the agent to infer or test.
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%, with both parameters clearly documented as entity names or points. The description adds no additional parameter semantics beyond what the schema provides, such as examples of valid entities or distance calculation specifics. Baseline 3 is appropriate given the comprehensive schema.
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 clearly states the tool's purpose: 'Measure minimum distance between two entities'. It specifies the verb ('measure'), resource ('distance'), and scope ('minimum', 'between two entities'). However, it doesn't explicitly differentiate from sibling tools like 'measure_angle' or 'check_interference', which also involve measurement or spatial analysis.
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 provides no guidance on when to use this tool versus alternatives. It doesn't mention sibling tools like 'measure_angle' for angular measurements or 'check_interference' for collision detection, nor does it specify prerequisites or typical use cases. The agent must infer usage from the tool name alone.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.