add_extruded_spline

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

Annotations already declare destructiveHint=true, readOnlyHint=false, non-idempotent and closed-world, so the safety profile is covered. The description adds the unit convention (mm/degrees/kg) and that the result carries verified measurements and error evidence, but never says what existing geometry may be affected or what a failure returns.

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 short sentences with the action front-loaded, so it is not bloated. However, the closing sentence about "verified measurements and error evidence" is opaque and does not translate into actionable information for the caller.

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?

This is a destructive geometry-mutating tool with zero parameter documentation and no output schema, so the description must carry a heavy load. It omits point ordering/planarity, the minimum three-point constraint, whether the extrusion adds to or replaces existing bodies, and what errors look like.

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% for all three parameters. The unit sentence gives mm context that the _mm suffixes already imply, but nothing explains that points_mm is a list of 2D [x,y] pairs with a minimum of 3 points, or that depth_mm must be strictly positive, or what name controls.

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?

"Add extruded spline" is a specific verb+resource pair, so an agent knows a spline-based extrusion is created. It does not differentiate itself from close siblings such as add_extruded_profile, add_swept_profile, or extrude_sketch, leaving the agent to guess which geometry primitive to choose.

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?

There is no statement of when to use this tool versus the many sibling profile/loft/sweep/extrude tools, and no preconditions (open document, active part) are given. "Inspect verified measurements and error evidence" hints at post-call behavior but is not usage guidance.

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