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

Annotations only give generic safety flags; the description adds substantive behavior beyond them: unit guessing with the guess reported back for correction, the response's watertight verdict, and the rule that a non-watertight mesh cannot participate in a boolean. This is exactly the context an agent needs before building on the import.

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 dense sentences, purpose front-loaded and each clause carrying information (format list, unit handling, watertight consequence). Slightly packed, but no sentence is filler.

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 7-parameter, zero-required tool with no output schema, the description covers the two things the response reports (unit guess, watertight status) plus the repair decision loop. An agent has enough to invoke it correctly and interpret the result.

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 100%, so the baseline is 3, but the description adds real meaning: pass `unit` when known or accept a reported guess, and the staged repair workflow tied to the `repair` parameter's default-off rationale. It reinforces the schema rather than merely restating 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 verb (import), resource (STL/OBJ/3MF mesh as a new project) and scope ('for geometry you did not author'), which cleanly separates it from siblings like import_2d, remix_project and the authoring tools. An agent can identify the tool without opening the schema.

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 phrase 'for geometry you did not author' gives a clear when-to-use criterion, and the repair sentence prescribes a concrete workflow (import once, read watertight, re-import with repair only if needed). It stops short of naming sibling alternatives (e.g. create_upload, remix_project) explicitly, so no exclusions are stated.

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