Create a reference axis through a point and direction or along the intersection of two planes for circular patterns.
A reference axis anywhere: through=[[x, y, z], [dx, dy, dz]] (point and direction, model mm) or where two planes meet (planes=['Plane1', 'right']).
Patterns turn about it by name (add_circular_pattern(axis=...)).
| Name | Required | Description | Default |
|---|---|---|---|
| name | No | ||
| planes | No | ||
| through | No |
Changes observed during successful MCP inspections.
v0.16.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full behavioral burden. It explains axis definition syntax and that the axis can be referenced by name in add_circular_pattern, but it does not state mutation/persistence behavior, validation rules when neither or both definition forms are supplied, or what happens on failure.
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 definition is compact and front-loads the two construction methods, with no wasted sentences. The opening phrase "A reference axis anywhere" is slightly indirect, but the parameter examples and downstream usage note are efficiently stated.
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 3-parameter CAD modeling tool with no annotations, no output schema, and 0% schema description coverage, the description covers the two main geometric inputs but omits the name parameter, optionality behavior, and constraints when both through and planes are provided. It is adequate to attempt a call but leaves meaningful gaps.
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 does this well for through (point and direction in model mm with an example) and planes (two named planes with an example). It leaves the name parameter unexplained and does not clarify mutual exclusivity or defaults for through/planes.
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 identifies the resource as a reference axis and gives the two defining constructions. It lacks an explicit verb such as "creates" and does not differentiate this from the sibling add_plane tool, but the axis-specific purpose is clear.
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?
It implies usage by showing the through-point/direction form and the intersecting-planes form, and notes that patterns can rotate about the axis by name. It does not explicitly say when to use this versus add_plane or when one construction form is preferable.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.