Selects the SolidWorks part face passing through specified model coordinates (x, y, z in mm); use get_bounding_box to find outer-face coordinates before selecting.
Selects the face of the part passing through the point (x, y, z) in mm, model coordinates. Use get_bounding_box to find the coordinates of the outer faces.
| Name | Required | Description | Default |
|---|---|---|---|
| x_mm | Yes | ||
| y_mm | Yes | ||
| z_mm | Yes |
| 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 non-destructive, idempotent, non-open-world behavior, so the safety bar is low. The description adds that coordinates are in model space and millimetres, but says nothing about behavior when no face lies at the point, or whether an existing selection is replaced or added to.
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 sentences, no filler; the operation and its units are stated first, with the prerequisite hint second. Every clause earns its place.
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?
An output schema exists, so return values need not be described, and the tool is inherently simple with three required scalars. The remaining gap is failure-mode behavior, which would matter for an agent probing internal geometry.
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 coverage is 0% and the properties carry only titles, so the description is the sole source of semantics. It supplies the two things that matter: the units (mm) and the coordinate system (model coordinates), which prevents an agent from passing drawing or screen coordinates.
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?
States a specific verb and resource ('Selects the face of the part') and qualifies it by an exact geometric condition (passing through a point). The face-vs-edge distinction from the sibling select_edge_at_point is implicit in the resource name but never called out explicitly.
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?
Gives a concrete prerequisite workflow: use get_bounding_box first to find coordinates of the outer faces, which tells the agent how to obtain valid arguments. It does not say when to avoid this tool, e.g. when selecting internal faces or when no geometry exists at the point.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.