Draw a polyline through specified x,y coordinates in millimeters. Optionally close the shape by connecting the last point to the first, and assign a layer.
Draw a polyline through [[x, y], ...] points (mm); closed=True joins last to first.
| Name | Required | Description | Default |
|---|---|---|---|
| layer | No | ||
| closed | No | ||
| points | Yes | ||
| fit_view | No |
| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the burden of behavioral disclosure. It usefully adds the mm unit and clarifies that closed=True joins the last point to the first. However, it does not disclose behavior for empty or single-point arrays, coordinate interpretation, or the effect of fit_view.
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 a single compact sentence that front-loads the core behavior, data format, units, and the key optional flag. Every element earns its place with no filler.
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 simple drawing tool with an output schema and obvious defaults, the description covers the essential input contract and the closed behavior. The main gaps are layer and fit_view semantics, but these are minor given the schema defaults and the low complexity of the 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 compensate. It explains the points array structure and the meaning of closed, but layer and fit_view are left entirely unexplained beyond their schema titles and defaults. This is only partial coverage of the four parameters.
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 concrete action ('Draw'), the resource ('polyline'), and the exact input format with units ('[[x, y], ...] points (mm)'). It clearly distinguishes this from sibling tools like create_line or create_rectangle.
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 intended use case of creating a multi-point polyline is implied by the description, but there is no explicit guidance about when to choose this over create_line or create_arc, and no mention of when not to use it. The usage context is inferable but not stated.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.