add_spline

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full burden. It mentions 'fitted spline' and 'optionally closed' but does not disclose whether the spline is a smooth curve through all points, how the closed option affects the curve, or any side effects like modifying the sketch. It also doesn't mention units or coordinate system beyond mm, which is helpful but minimal.

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 sentence that is concise and front-loaded with the core purpose. It includes the key details (points in mm, optional closed) without any fluff. Every word earns its place.

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?

Given the tool has 3 parameters, no output schema, and no annotations, the description is adequate but not complete. It covers the main purpose and the 'closed' option but does not explain the 'sketch' parameter or the exact structure of 'points'. For a simple spline tool, this is acceptable but could be improved with more detail on the points format and sketch context.

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 'points' as a list of [x, y] points in mm and 'closed' as optional, but does not detail the format of the points array (e.g., nested arrays, objects) or the 'sketch' parameter (which is required but not described). The description adds some meaning but leaves gaps for the required 'sketch' parameter.

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 adds a fitted spline through a list of [x, y] points in mm, with an optional closed parameter. It distinguishes from sibling tools like add_line, add_arc, add_polygon by specifying 'fitted spline' and the point list input.

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 implies usage in a sketching context (points in mm, optional closed) but does not explicitly state when to use this vs alternatives like add_polygon or add_arc. No exclusions or alternative tool references are provided, but the context is clear enough for a basic spline creation.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.