mirror_part

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

The annotation destructiveHint=false declares only additive updates, yet the description states 'Voxels on the replaced side are discarded,' which is a destructive update to the model. This directly contradicts the annotation, so the transparency score is pinned at 1 despite the otherwise useful disclosure of the default-plane behavior and the wheel limitation.

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 core action is front-loaded in the first sentence, followed by the geometric behavior, workflow, and exception in a logical order. Four short sentences with essentially no filler, though the trailing parenthetical aside is slightly awkward.

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?

For a mutation tool with no output schema and fully documented parameters, the description covers purpose, geometric effect, a data-loss warning, and an edge-case exclusion. The main omission is permission/error behavior and what happens if the part spans the plane asymmetrically, but the essentials are present.

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 100% (each of the four parameters is documented, including the 'keep' enum mapping to X below the plane), so the schema already carries the load. The description adds only the geometry framing of the default plane X = 0 and the -8..8 example, which is modest value over the schema.

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 first sentence gives a specific verb and resource ('Make a body part left-right symmetric: copy one side, mirrored, over the other side'), which is unambiguous. It partially differentiates from siblings by noting that wheel parts are handled by add_wheels, but it does not contrast against other geometry tools like move_part or hollow_part.

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?

It provides a concrete workflow ('Model details on the left side, then mirror') and a clear when-not case ('Wheel parts cannot be mirrored (add_wheels already makes both sides)'). There is no explicit statement of prerequisites (e.g., the part must already exist) or a named alternative for non-body parts, so it stops short of full routing guidance.

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