MCP 3D Printer Server

modify_stl_section

Apply scale, rotate, or translate transformations to a chosen top, bottom, center, or custom section of an STL file for 3D printing preparation.

Instructions

Apply a specific transformation to a selected section of an STL file

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": {
      "stl_path": "<stl_path>",
      "section": "<section>",
      "transformation_type": "<transformation_type>"
    },
    "name": "modify_stl_section"
  }
}

Input Schema

Name	Required	Description
`section`	Yes	Section to modify: 'top', 'bottom', 'center', or custom bounds
`value_x`	No	Transformation value for X axis
`value_y`	No	Transformation value for Y axis
`value_z`	No	Transformation value for Z axis
`stl_path`	Yes	Path to the STL file
`custom_max_x`	No	Maximum X for custom section bounds
`custom_max_y`	No	Maximum Y for custom section bounds
`custom_max_z`	No	Maximum Z for custom section bounds
`custom_min_x`	No	Minimum X for custom section bounds
`custom_min_y`	No	Minimum Y for custom section bounds
`custom_min_z`	No	Minimum Z for custom section bounds
`transformation_type`	Yes	Type of transformation to apply

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.2.9Sep 29, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations, the description carries the full behavioral burden, but it only implies a write operation via 'Apply'. It does not say whether the file is modified in place, whether the original is overwritten, what happens to geometry outside the section, what units or coordinate system apply, or how errors are handled.

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 a single, front-loaded sentence with no wasted words. It communicates the core action immediately and does not bury the purpose in extra text.

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

Completeness2/5

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

Given 12 parameters, two enums, no annotations, and no output schema, the description is incomplete. It does not explain how to interpret the transformation values, when custom bounds apply, file-side effects, or expected outcomes, leaving the agent heavily dependent on the schema and trial-and-error.

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%, and the schema documents all parameters including enums for section and transformation_type, axis values, and custom bounds. The description adds no parameter meaning beyond what the schema already provides, so a baseline 3 is appropriate.

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

Purpose4/5

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

The description states a specific verb ('Apply'), a specific resource ('STL file'), and a specific scope ('selected section'), which distinguishes it from whole-file siblings like scale_stl, rotate_stl, and translate_stl. However, it does not explicitly name those alternatives, so it falls short of the top score.

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

Usage Guidelines2/5

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

The description offers no guidance on when to use this tool versus alternatives, when to choose section-based modification versus whole-file transforms, or prerequisites such as valid STL paths or coordinate-system expectations. Usage is only implied by the phrase 'selected section'.

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