Evaluate FeatureScript expressions in an Onshape Part Studio to query geometry, using document, workspace, element IDs and a script expression.
Evaluate a FeatureScript expression in a Part Studio (read-only, for querying geometry)
| Name | Required | Description | Default |
|---|---|---|---|
| script | Yes | FeatureScript lambda expression to evaluate | |
| elementId | Yes | Part Studio element ID | |
| documentId | Yes | Document ID | |
| workspaceId | Yes | Workspace ID |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations present, the description carries the full burden. It mentions 'read-only' which is a behavioral trait, but does not detail error handling, side effects, or permission requirements.
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 extremely concise and to the point, conveying the essential functionality without any unnecessary words or formatting issues.
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?
Since there is no output schema, the description could have mentioned what the evaluation returns, but the simple nature of the tool and the 'querying geometry' hint make it adequate. However, it lacks explicit details about expected results.
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?
The schema provides descriptions for all parameters, so schema coverage is 100%. The tool description adds no extra meaning beyond the schema, hence the baseline score of 3.
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 tool evaluates a FeatureScript expression in a Part Studio, with a specific verb and resource. It distinguishes itself from the sibling 'write_featurescript_feature' by noting its read-only nature.
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?
There is no explicit guidance on when to use this tool versus alternatives. The phrase 'read-only, for querying geometry' provides some context but does not name or compare with other tools.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.