formlabs-local-mcp

detect_thin_walls

Read-only

Find wall regions thinner than a specified threshold in 3D models, returning their volumes and bounding boxes to identify potential print failures before slicing.

Instructions

Find wall regions thinner than threshold_mm per model, with volumes and bounding boxes.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "threshold_mm": "<threshold_mm>"
    },
    "name": "detect_thin_walls"
  }
}

Input Schema

Name	Required	Description	Default
`models`	No	"ALL" or a list of model ids	ALL
`scene_id`	No	Scene id; omit for the default scene	default
`threshold_mm`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.4Sep 16, 2026

TDQS

A4.2/5.0

Behavior4/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds useful behavior beyond that: it operates per model and returns volumes and bounding boxes, which are not captured in 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.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

One concise, front-loaded sentence with no filler. It states the action, the key parameter, the scope, and the output in a compact way.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a read-only detection tool with three parameters and no output schema, the description covers the main input, scope, and output types. Minor gaps remain around exact return structure and behavior when no thin walls are found, but the core call is clear.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema descriptions cover models and scene_id, but threshold_mm has no description beyond exclusiveMinimum. The description clarifies that threshold_mm is the thickness cutoff, adding meaning to the required parameter.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Find') and resource ('wall regions thinner than threshold_mm'), plus the output type ('volumes and bounding boxes'). This clearly distinguishes it from sibling detection tools like detect_cups or detect_minima.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Usage is implied by the purpose: use this when you need to detect thin walls in models. However, there is no explicit when-to-use/when-not-to-use guidance or mention of alternatives, so the agent must infer selection from the name and description.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.