Draws an arc in a SolidWorks sketch using center, start, and end points in millimeters, with an optional counterclockwise direction.
Draws an arc given centre, start point and end point (mm).
| Name | Required | Description | Default |
|---|---|---|---|
| end_x_mm | Yes | ||
| end_y_mm | Yes | ||
| start_x_mm | Yes | ||
| start_y_mm | Yes | ||
| center_x_mm | Yes | ||
| center_y_mm | Yes | ||
| counterclockwise | No |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare that this is a non-read-only, non-destructive, non-idempotent, closed-world mutation. The description adds that coordinates are in millimetres, which is useful context. However, it does not disclose prerequisites, the effect of the optional counterclockwise flag, or any other behavioral constraints beyond the annotations.
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 one-sentence description is front-loaded and contains no wasted words. It is appropriately compact, though its brevity contributes to missing important parameter and usage details.
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 sketch mutation with 7 parameters and 0% schema description coverage, the description is too thin. It does not state that an active sketch is required, does not explain the counterclockwise option, and does not clarify how the start and end points determine the arc sweep. Output schema exists, so return values need not be described.
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 0%, so the description must compensate. It identifies the roles of centre, start and end points and mentions units, but it completely omits the optional counterclockwise parameter and does not clarify coordinate system or orientation semantics. This is insufficient for a 7-parameter geometry tool.
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 and resource: drawing an arc from centre, start and end points. It is clearly distinguishable from sibling sketch tools such as sketch_line or sketch_circle by the arc geometry. It does not explicitly mention that this must occur inside an active sketch, which keeps it from a 5.
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?
There is no guidance on when to use sketch_arc versus alternatives such as sketch_spline, sketch_circle or sketch_polygon. It also omits prerequisites like requiring an active sketch. Only the geometry itself implies intended usage.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.