Assign a real material by name to replace the default density and get accurate mass properties, including density and mass.
Assign a material by name (e.g. "6061 Alloy", "AISI 1020", "ABS").
Makes mass and density reflect a real material instead of the 1000 kg/m³ default. Returns mass properties including density.
| Name | Required | Description | Default |
|---|---|---|---|
| name | Yes | ||
| database | No |
Changes observed during successful MCP inspections.
v0.4.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description must disclose behavioral traits on its own. It explains that mass and density are updated and that mass properties are returned, but it does not mention potential failure modes (e.g., invalid material name) or the effect of the database parameter. This is adequate but not comprehensive.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
The description is concise and front-loaded: the first sentence states the action, the second explains the effect and return. There is no wasted text.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
The tool is a simple setter, but the description omits documentation for the 'database' parameter and does not specify behavior on invalid input. While the main effect is covered, the missing parameter explanation makes it incomplete for a no-output-schema tool.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema description coverage is 0%, so the description must explain parameters. It clarifies the 'name' parameter with examples but says nothing about the 'database' parameter. This leaves a gap for an agent trying to populate that field correctly.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
The description clearly states the action ('Assign a material by name') with specific examples, and it distinguishes from sibling tools like get_mass_properties by focusing on setting versus reading. It is unambiguous about the resource being modified.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
The description indicates when to use the tool ('instead of the 1000 kg/m³ default'), implying it is for assigning realistic materials. It does not explicitly mention alternatives or when not to use it, but the context is clear enough for an agent to understand its purpose.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.