Render polylines without drawing to preview pen-up travel, page bounds, and simulated ink marks before plotting.
Render polylines (canvas mm, [[ [u,v], ... ], ...]) without drawing. Returns the diagnostic view (pink = pen-up travel, grey box = page) and, with simulate=true (default), what the arm will actually put on paper.
| Name | Required | Description | Default |
|---|---|---|---|
| paths | Yes | ||
| simulate | No |
Changes observed during successful MCP inspections.
v0.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover read-only, idempotent, non-destructive, and closed-world behavior. The description adds genuine value beyond them: it discloses what is returned (diagnostic view with pink pen-up travel, grey page box) and that simulate=true is the default that shows what the arm will actually draw.
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 sentences, front-loaded with the core action and format before the return-value detail. Every clause 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?
No output schema exists, so the description correctly explains the return (diagnostic view and simulation). It is sufficient for a read-only preview tool, though it omits details like units per segment beyond 'canvas mm' and whether the view is returned as an image or structure.
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 coverage is 0%, so the description must carry parameter meaning, and it does: it documents the nested paths format ('canvas mm, [[[u,v], ...], ...]') and explains that simulate (default true) controls whether the simulated on-paper result is shown. This compensates well for the empty schema descriptions.
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?
States a specific verb+resource (render/preview polylines) and clarifies scope with 'without drawing', which distinguishes it from the draw_* siblings. The input format is also given inline. It stops short of naming the draw_paths alternative explicitly, but the intent is unambiguous.
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?
'Without drawing' implies this is the preview counterpart to draw_paths, so usage is inferable. However, there is no explicit when-to-use/when-not guidance or named alternative, leaving the agent to infer the preview-vs-draw choice.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.