add_extruded_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 discloses that the spline is auto-closed, that volume is measured rather than analytic, and that mass properties are returned. It also notes the prerequisite of new_part. These go beyond the schema and give useful behavioral context.

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?

Three sentences, no fluff. The first sentence states the action and inputs, the second differentiates from a sibling, and the third covers a key behavioral note and return value. Every sentence 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?

No output schema exists, so the description must explain returns; it does ('Returns mass properties'). It also notes the measured volume. It lacks details on potential errors or edge cases, but for a creation tool with clear prerequisites and behavior, it is reasonably complete.

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 compensate. It explains the format of points_mm ([[x,y], ...] in mm) and that depth_mm is the extrusion depth. It does not describe the optional name parameter, but that is minor. The main required parameters are well explained.

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: extrude a smooth CLOSED spline through points. It clearly distinguishes itself from the sibling add_extruded_profile by specifying the smooth curve nature, and mentions the inputs and output. An agent can immediately understand what it does and how it differs.

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?

Provides a direct contrast with add_extruded_profile ('Like add_extruded_profile but...') and gives examples of use cases (cams, rounded outlines, aesthetic bosses). Also instructs 'Use new_part first.' It doesn't explicitly list when not to use other tools, but the main alternative is clearly differentiated.

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