bom

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

With no annotations present, the description carries the load and does disclose a real side effect — passing path writes a semicolon-separated UTF-8 CSV file to disk. It also implies the operation targets the active assembly, but says nothing about error behavior when no assembly is open or whether generation itself is read-only.

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?

Front-loaded with the resource and returned columns, then a single-sentence usage note, then a compact per-argument block. Every sentence adds information; nothing is repeated from the schema.

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 no explanation, and all three parameters are accounted for between description and schema. The main remaining gap is the absence of any note on preconditions (an active assembly must exist) for a tool that writes an external file.

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 coverage is only 33%, but the description compensates well: it defines both view modes ('parts_only' = every part once with total quantity vs 'structured' = indented sub-assemblies) and explains that path triggers a CSV write with UTF-8 and ';' separators. Only 'instance' is left to the schema, which already documents it.

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 resource (bill of materials of the active assembly) and enumerates the exact columns produced (item, quantity, part number, material, mass, file). No sibling tool overlaps, so an agent can identify it immediately.

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?

Gives a concrete use case ('For purchasing / ERP') and a prerequisite that routes to a sibling: 'set part numbers and descriptions first with properties()'. It does not state when not to use it or what happens if no assembly is active, so it stops short of full when/when-not guidance.

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