Identify a planar face's plane, including a point, in-plane directions, and outward normal, to determine the correct face for sketching.
For a planar face, report its plane: a point on it, its two in-plane directions and the outward normal. This is what you need to decide which face is 'the top one' before sketching on it.
| Name | Required | Description | Default |
|---|---|---|---|
| face | Yes | Reference token of the face. |
Changes observed during successful MCP inspections.
v1.0.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and destructiveHint=false, and the description adds value by specifying the input must be planar and by detailing the returned components, including the outward normal's orientation. It does not mention failure behavior for non-planar faces, but this is implied by the precondition.
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 two tight sentences: the first defines the tool's action and output, the second gives the motivating use case. No filler or repetition; the key benefit is front-loaded.
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?
With no output schema, the description carries the full burden of describing return values, and it does so clearly. The read-only annotations cover safety, the single parameter is documented, and the tool's role in the sketcher workflow is explicit, making it complete for this low-complexity tool.
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?
The schema already describes 'face' as a reference token, and the description adds the crucial constraint that the face must be planar, which affects how the parameter should be chosen. Since schema coverage is 100%, the description provides useful extra semantics beyond the baseline.
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 uses a specific verb ('report') and a clear resource ('plane of a planar face'), enumerating the exact outputs: point, two in-plane directions, outward normal. It also gives a concrete use case (deciding the top face before sketching) that separates it from sibling tools like catia_measure or catia_gsd_plane.
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 explicitly states when to use this tool: when you need to decide which face is 'the top one' before sketching on it. It provides clear context but does not name alternatives or say when not to use it, so it falls short of full routing guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.