mat_create_arnold

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

Annotations already mark this as a mutating tool (readOnlyHint=false, destructiveHint=true), so mutation is known. The description adds genuinely useful behavioral context beyond the annotations: Arnold must be installed, otherwise the tool returns a class_missing error, and the agent should probe availability first. It does not detail every side effect, but it covers the critical non-obvious behavior.

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 compact and front-loaded: it states the core action first, then the critical Arnold dependency, then the recommended probe step. The bilingual duplication is acceptable for the target audience and does not add unnecessary length. Every sentence carries useful information.

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 low-complexity tool with full schema coverage, the description covers the main non-obvious context: availability, error behavior, and how to probe. The main remaining gap is that the tool has zero required parameters, so it is unclear what happens if name is omitted, and no return value is described. These are minor relative to the critical dependency warning.

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 100%, so the schema already explains 'name' and 'objects'. The description's mention of assigning objects after creation repeats the schema's own explanation rather than adding new meaning. There is no additional detail about optionality or default behavior when name is omitted, so the description does not elevate above the structured schema.

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: 'Create an Arnold material (aiStandardSurface)'. It also distinguishes itself from sibling material creators like mat_create_standard, mat_create_vray, and mat_create_physical by naming the exact shader type. The distinctive Arnold availability caveat further removes ambiguity.

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 description explicitly states when the tool can be used: only when Arnold is installed. It also names the failure mode (class_missing error) and recommends probing first with list_render_engines / does_class_exist, which are actual sibling tools. This gives an agent clear actionable guidance for selecting this tool over alternatives.

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