import_usd

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

Annotations already indicate this is destructive, so the description doesn't need to restate that. It adds valuable behavioral context by disclosing that the call fails with err.class_missing when the USD plugin is absent. It does not describe merge side effects, but the schema already documents the merge parameter.

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 description is just two short sentences, front-loaded with the action and immediately followed by the key plugin caveat. No filler or redundant expansion.

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?

It covers the essential plugin prerequisite and the resulting error, and the schema handles parameters. It does not state what happens on success or whether merge=false replaces the scene, so it isn't a 5, but it is adequate for a simple import call.

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?

The input schema has 100% description coverage for both parameters, so the description adds no extra meaning beyond what the schema already provides. Baseline 3 is appropriate.

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 states a specific verb and resource ('Import USD' / '导入 USD'), which clearly distinguishes it from sibling importers such as import_fbx, import_obj, and import_gltf by file format. The plugin caveat does not obscure the core function.

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?

Usage is implied: call it when importing a USD file. It provides a precondition (USD plugin must be installed) and a failure code, but it does not explicitly tell when to choose this tool over import_merge_scene or other format-specific importers.

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