nx_shell

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

With no annotations at all, the description carries the full burden. It does disclose two real behavioral traits: only a single face is removed in this version, and inward=True preserves outer dimensions. It does not disclose failure modes, required permissions, or what happens to the removed face's geometry beyond the opening.

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?

Two compact sentences, front-loaded with the core operation before the qualifiers. 'First version removes a single face' is slightly awkward phrasing but carries genuinely useful scoping information, so little is wasted.

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?

An output schema exists, so return values need not be described, and the core geometry semantics are covered. However, for a mutation tool with no annotations and zero schema descriptions, the definition should say more about preconditions and how to obtain the face index.

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 inward (preserves outer dimensions) and implicitly clarifies thickness and remove_face_index through 'constant wall thickness' and 'remove one face as an opening', but leaves body_id and the source/format of the face index (presumably from nx_list_faces) unaddressed.

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 ('Shell (hollow) a body') and immediately explains the mechanism: removing one face as an opening while keeping a constant wall thickness. This is clearly distinguishable from sibling operations like nx_hole or nx_extrude.

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 operation's purpose implies when it is appropriate (hollowing a solid body), but there is no explicit guidance on when to choose this over alternatives such as cutting with an extrude, nor any stated prerequisites (e.g. body must be solid, body must exist).

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