view_partOpen an STL part in an interactive 3D viewer to rotate, zoom, and measure its bounding box, while returning a text summary of triangle count and dimensions.
Open an STL part in an interactive 3D viewer (rotate, zoom, measure the bounding box). Returns a text summary with triangle count and dimensions as well.
| Name | Required | Description | Default |
|---|---|---|---|
| path | Yes | Path to an .stl file, relative to the viewer's root folder |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are supplied, so the description carries the full behavioral burden. It does disclose the side effect of opening an interactive viewer and the fact that a text summary is also returned, which is genuinely useful. However, it says nothing about whether the viewer blocks, whether a GUI/display is required, file-size limits, or how missing or malformed .stl files are reported.
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?
Two compact sentences with the primary action front-loaded and the return behavior appended where it belongs. Nothing is padded, though the parenthetical capability list is slightly dense and could be ordered more usefully.
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?
For a one-parameter, no-output-schema tool, the definition covers the action, the interactive capabilities, and the shape of the returned summary. The only meaningful omission is error and environment behavior, which matters but is secondary for a read-only viewer.
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 100% and the single 'path' parameter is already documented as root-relative in the schema, so the baseline of 3 applies. The description adds only weak reinforcement ('STL part') and no extra semantics such as accepted extensions or path normalization rules.
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 names a specific verb and resource ('Open an STL part in an interactive 3D viewer') and states what the call yields (a text summary with triangle count and dimensions). There are no sibling tools to disambiguate against, so the only thing keeping it from a 5 is that the phrase 'view_part' vs. the interactive viewer's scope is not further bounded.
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?
Usage is only implied by the description of the action; there is no explicit statement of when to choose this tool, what prerequisites exist (a viewer session, a valid root-relative file), or what to do on failure. With no siblings, the absence of alternatives is acceptable, but the lack of preconditions leaves guidance thin.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.