formlabs-local-mcp

save_screenshot

Destructive

Render the current 3D scene to a PNG or WebP file at a specified absolute path, with options for camera angle, zoom, and image size.

Instructions

Render the scene to a .png or .webp at an absolute path. view_type is ZOOM_ON_MODELS, FULL_BUILD_VOLUME or FULL_PLATFORM_WIDTH.

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": {
      "file": "<file>"
    },
    "name": "save_screenshot"
  }
}

Input Schema

Name	Required	Description	Default
`yaw`	No
`file`	Yes
`pitch`	No
`scene_id`	No	Scene id; omit for the default scene	default
`view_type`	No		ZOOM_ON_MODELS
`image_size_px`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.0.4Sep 16, 2026

TDQS

B3.1/5.0

Behavior2/5

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

Annotations already declare destructiveHint=true, so the write nature is known. However, the description adds no additional behavioral context, such as whether an existing file is overwritten, whether the file must be .png or .webp specifically, or if any permissions are needed. It simply restates the action without enriching the annotation-provided safety profile.

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 two sentences with no fluff. It front-loads the core action and then provides the enum values for view_type. Every sentence earns its place and there is no redundancy.

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?

For a tool with 6 parameters, 1 required, no output schema, and sparse annotations, the description is far too thin. It does not explain yaw, pitch, image_size_px, or the file path semantics, nor does it mention defaults or how the scene_id default works. An agent would struggle to construct a correct call without additional schema or tooling hints.

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

Parameters2/5

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

Schema description coverage is only 17% (only scene_id has a description). The description does explain view_type and its enum values, which is helpful, but it does not clarify the meaning or format of yaw, pitch, image_size_px, or the required file parameter. With low coverage, the description should compensate for all undocumented parameters, but it only addresses one.

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 states a specific verb (Render), a resource (the scene), and the output format (.png or .webp) at an absolute path. It also names the view_type enum values, which clearly distinguishes this tool from all siblings, none of which perform screenshot rendering.

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?

No guidance is given on when to use this tool versus alternatives. There are no similar sibling tools, but the description does not mention any context like 'use this to capture an image for documentation' or any prerequisites. The agent must infer usage solely from the name and purpose.

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