add_shell

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

Annotations already declare destructiveHint=true, readOnlyHint=false, and idempotentHint=false, so the safety profile is covered structurally. The description adds two pieces of real context beyond that: the unit convention (mm, degrees, kg) and the fact that verified measurements and error evidence are surfaced for inspection. It still omits which body is modified and whether the operation is reversible or absorbs the original solid.

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, front-loaded with the operation, which is good. However, "through the independent native SOLIDWORKS engine" is promotional filler and "Inspect verified measurements and error evidence" is too vague to earn its place without explaining what is returned.

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 mutation with two parameters at 0% schema coverage and no output schema, which sets a high bar. The description leaves the target body, the effect of open_face, failure modes, and the nature of the "verified measurements" unaddressed, so an agent cannot call it confidently from the description alone.

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 carries the full burden. It only establishes that thickness_mm is in millimetres; it says nothing about the meaning or accepted values of open_face (defaulting to "+z"), which faces can be opened, or the exclusiveMinimum constraint on thickness.

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 description names a specific verb and resource ("Add shell") and identifies the engine, but it never says what a shell operation actually produces (hollowing an existing solid to a wall thickness) or which body it applies to. It is not distinguishable from the many other add_* feature tools beyond the word "shell".

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 guidance on when to use this versus alternatives such as cut_profile, cut_offset_pocket, or cut_slot, all of which also remove material. No prerequisites are stated either, such as requiring an existing solid body or an active document.

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