add_rib

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

With no annotations, the description carries the full burden, and it does so well: it explains how the rib grows toward toward_mm until meeting the part, how thickness is applied, and that it returns mass properties. It doesn't mention prerequisites like an active part or failure modes, but it discloses the key behavioral and return characteristics.

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 well-structured and front-loaded with the purpose, then parameter semantics, then return behavior. Each sentence provides distinct value, and the mass-properties formula earns its place because it tells the agent what result to expect.

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 no annotations, no param descriptions, and no output schema, the description is remarkably complete for a CAD primitive tool. It covers the geometry, all key parameters, and the return. Minor gaps are the lack of an explicit prerequisite that a part must be open and no discussion of failure conditions if the rib never meets the part.

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%, yet the description explains almost every meaningful parameter: start_mm/end_mm as [x,y] endpoints, z_mm as plane height, toward_mm as the fill direction, and thickness_mm as the rib thickness. It also ties coordinates to add_extruded_profile, which helps an agent understand the expected format.

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 and resource: adds a straight stiffening rib/gusset in a plane parallel to the Front plane. The geometric detail and the mention of 'rib/gusset' differentiate it clearly from generic extrusion or sweep siblings.

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?

Usage is implied by the clear domain language ('stiffening rib / gusset'), and the coordinate reference to add_extruded_profile gives some context. However, it does not explicitly state when to prefer this over alternatives like add_extruded_profile or add_swept_profile, nor does it mention exclusions.

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