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by com.owlcad.mcp
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Check printability

print_check
Read-onlyIdempotent

Analyse a model for 3D-printing problems: overhang area beyond the safe angle, and the thinnest wall. Use this before calling a part done — it is the check you cannot do by reasoning about the tree, and evaluate does not answer it. If the request mentions supports, overhangs, thin walls, or whether a part fits the bed or will print at all, this tool is the only thing that answers it.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
scadNoOpenSCAD source, as an alternative to `nodes` (supply exactly one). Interpreted by the same engine the editor’s .scad import uses; BOSL2/MCAD includes resolve. minkowski() and resize() are not supported here — use hull() or offset().
nodesNoParametric node tree. mm, Z-up, rotations in DEGREES (a rotation.* binding: radians). Read owlcad://schema/primitives for every primitive, modifier and generator and its parameter ranges (unknown params are dropped silently), and owlcad://schema/conventions for the placement arithmetic, which is where most models go wrong.
minWallMmNoThinnest acceptable wall in mm (default 0.8).
printerIdNoCheck whether the model fits a specific printer’s build volume. Ids come from the owlcad://printers resource.
projectIdNoId of one of your saved projects, as an alternative to `nodes`/`scad` (supply exactly one).
smoothnessNoCurve quality for shapes that left their segment count automatic. Defaults to "standard", which is the editor default — pass "high" to match a project authored at high smoothness, "draft" for a cheaper check.
overhangDegNoOverhang angle treated as unsupported (default 45).

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changed
    • changedInput schema / properties / nodes / description
      Previous value: -"Parametric node tree. mm, Z-up, rotations in DEGREES. Read owlcad://schema/primitives for every primitive, modifier and generator and its parameter ranges (unknown params are dropped silently), and owlcad://schema/conventions for the placement arithmetic, which is where most models go wrong."New value: +"Parametric node tree. mm, Z-up, rotations in DEGREES (a rotation.* binding: radians). Read owlcad://schema/primitives for every primitive, modifier and generator and its parameter ranges (unknown params are dropped silently), and owlcad://schema/conventions for the placement arithmetic, which is where most models go wrong."
  2. Changed1 schema field changed
    • changedInput schema / properties / nodes / items / properties / generatorKey / description
      Previous value: -"Generator to expand (kind=generator). PREFER one over hand-building the same thing — they carry standards dimensions and solve fits a tree of primitives gets subtly wrong: gearTrain · planetary · rackPinion · wormDrive · herringbone · herringboneTrain · pulley · bearing · belt · spring · adapter · boardMount · enclosure · gridfinity · threadedJar · pinHinge · snapFit · ballSocket · fastener · textPlate · fitCoupon · calibrationBlock · clamp · impeller · axialFan · fanFrame · plugCap."New value: +"Generator to expand (kind=generator). PREFER one over hand-building the same thing — they carry standards dimensions and solve fits a tree of primitives gets subtly wrong: gearTrain · planetary · rackPinion · wormDrive · herringbone · herringboneTrain · pulley · bearing · belt · spring · adapter · boardMount · enclosure · gridfinity · threadedJar · pinHinge · snapFit · ballSocket · fastener · textPlate · fitCoupon · calibrationBlock · clamp · impeller · axialFan · fanFrame · plugCap · pillowBlock."
  3. Changed1 schema field changed
    • changedInput schema / properties / scad / description
      Previous value: -"OpenSCAD source, as an alternative to `nodes` (supply exactly one). Interpreted by the same engine the editor’s .scad import uses. minkowski() and resize() are not supported here — use hull() or offset()."New value: +"OpenSCAD source, as an alternative to `nodes` (supply exactly one). Interpreted by the same engine the editor’s .scad import uses; BOSL2/MCAD includes resolve. minkowski() and resize() are not supported here — use hull() or offset()."
  4. First observed

TDQS

A4.1/5.0
Behavior3/5

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

Annotations already declare readOnly, idempotent, non-destructive, so the safety profile is covered. The description adds that this is a check that cannot be done by reasoning about the tree, but says nothing about return shape, cost, or the printerId fit-check behavior beyond what the schema states.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

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

Front-loaded with the verb and the two checks, then usage. Three sentences, each earning its place, though the final sentence partially restates the second.

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?

No output schema exists, so the description could hint at what the analysis returns (measurements vs pass/fail), which is a minor gap. Otherwise, with annotations covering safety and the schema covering all params, an agent has enough to invoke correctly.

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

Parameters3/5

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

Schema description coverage is 100%, so the schema already documents all 7 parameters, including overhangDeg, minWallMm and printerId. The description's mention of overhangs, thin walls and bed fit maps to those params but adds no syntax or format detail beyond the schema; baseline 3.

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?

States a specific verb and resource — analyses a model for two named printability problems (overhang area beyond safe angle, thinnest wall). It also explicitly distinguishes itself from the sibling `evaluate`, which an agent can use to route correctly.

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

Usage Guidelines5/5

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

Gives explicit when-to-use ('before calling a part done'), names the alternative it is not (`evaluate` does not answer it), and enumerates triggering request terms (supports, overhangs, thin walls, bed fit). This is a textbook routing statement.

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

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