@placraftic/mcp-server

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list_materials

Retrieve 3D printing materials with pricing, colors, technology, and stock status. Filter by color, technology, or in-stock availability to select filaments and resins for orders.

Instructions

List all available 3D printing materials (filaments, resins) with pricing, color, technology, and stock status

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_materials"
  }
}

Input Schema

Name	Required	Description
`color`	No	Filter materials by color name (case-insensitive substring)
`technology`	No	Filter materials by technology code (e.g. 'fdm', 'sla', 'sls')
`inStockOnly`	No	When true, only returns materials with positive stock quantity

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 11, 2026

TDQS

B3.4/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full burden. 'List all' implies a read operation, but the description doesn't state permissions needed, pagination behavior, whether results are cached, or sorting order. For a list tool with zero annotation coverage, this is a significant gap.

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?

Single sentence, no waste, front-loaded with the core action. Slightly packed but effective.

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

Completeness3/5

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

Adequate for a simple list tool with 3 optional params and 100% schema coverage, but with no annotations and no output schema, the description doesn't cover behavioral aspects like pagination or return format. Missing prerequisites or usage context that would help an agent call 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 coverage is 100%, so baseline is 3. The description mentions color, technology, and stock status as returned fields and the schema documents the corresponding filters, but the description adds no syntax or format details (e.g., color matching is case-insensitive substring, technology codes like 'fdm') beyond what the schema already provides.

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 (list) and resource (materials), and specifies scope and returned fields (filaments, resins with pricing, color, technology, stock status). Clearly distinguishable from the sibling 'get_material' (single item) and unrelated list_* tools.

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?

Implied usage from the name and description — it lists all materials, with filterability via the schema parameters. However, there's no explicit guidance on when to use this vs. 'get_material' for a single item, or when not to use it.

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