Skip to main content
Glama

shell_solid

Hollow a solid into a thin-walled shell by removing specified faces and setting a wall thickness that grows inward, preserving the part's outer dimensions.

Instructions

Hollow a raw Part solid into a thin-walled shell (the direct-shape counterpart to thickness, which only works on PartDesign bodies).

handle: handle of the solid to hollow (e.g. a box/cylinder from add_primitive, or any shaped Part::Feature). faces: NON-EMPTY list of the faces to REMOVE — these become the shell's openings. Each entry is a face tag (f_..., from list_faces/query_faces, preferred and edit-stable), a 'FaceN' string, or a 1-based integer index. thickness: wall thickness in mm, must be > 0. The wall is grown INWARD, so the part's outer dimensions are preserved.

The consumed input solid is hidden (its geometry now lives in the shell). Returns {handle (starts 'shell_'), name, volume (mm^3 of the resulting walls), wall_thickness (mm), removed_faces (list of 1-based face indices that were opened)}. Raises if faces is empty, thickness <= 0, an index is out of range, or the offset is too large to produce a valid shell.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
nameNoShell
facesYes
handleYes
thicknessYes

Schema Changelog

Changes observed during successful MCP inspections.

  1. First observed

TDQS

A4.8/5.0
Behavior5/5

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

With no annotations provided, the description carries the full behavioral burden and does so well. It discloses that the input solid is consumed and hidden, that the wall grows inward preserving outer dimensions, what the return object contains, and the specific error conditions (empty faces, non-positive thickness, out-of-range index, invalid shell offset).

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?

The description is front-loaded with the core action and sibling differentiation, then methodically covers parameters, side effects, returns, and error conditions. Every sentence adds useful information without padding, and the structure is easy to scan.

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 mutation tool with no annotations and no output schema, the description supplies side effects, return shape, and failure modes. It is nearly complete, but the omission of the `name` input parameter leaves a small gap given 0% schema description coverage.

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 description coverage is 0%, so the description must document parameters. It thoroughly explains `handle`, `faces` (accepted formats, preferred edit-stable tags, non-empty requirement), and `thickness` (units, positive constraint, inward growth). However, the optional `name` parameter is never described in the input context, leaving one of four parameters undocumented.

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 and resource: 'Hollow a raw Part solid into a thin-walled shell.' It immediately distinguishes itself from the `thickness` sibling by scoping to raw Part solids rather than PartDesign bodies. An agent can identify the operation and its domain without opening the schema.

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?

It explicitly names the alternative (`thickness`) and the condition that selects it: `thickness` only works on PartDesign bodies, while `shell_solid` is the direct-shape counterpart. It also states required usage constraints: `faces` must be non-empty, and `thickness` must be greater than zero.

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

Deploy Server

Other Tools