rhino_list_materials

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

Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false, so the safety profile is fully covered. The description adds no additional behavioral context (e.g., ordering, format, side effects), but it does not need to given the simplicity and the presence of an output schema. It does not contradict annotations.

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 a single, compact sentence with no filler. It front-loads the action and the resource, and every word contributes to the meaning. This is optimal conciseness for a zero-parameter listing tool.

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 simple read-only listing tool with no parameters and an output schema present, the description fully covers what an agent needs to invoke it correctly. The output schema handles return-value details, and annotations cover side effects. No additional context is missing.

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 tool has zero parameters, and schema coverage is 100% (vacuously). There is nothing for the description to explain about parameters, so the baseline of 4 applies. No parameter information is needed beyond what the schema shows.

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 ('List') and resource ('all render materials in the document'), which is unambiguous and clearly differentiates it from other material-related tools in the sibling list (e.g., create_material, assign_material) since none of those list materials. The scope is explicit (all materials in the current document).

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 does not explicitly name alternatives or give when-not-to-use guidance, but there is no competing list-material tool among siblings, so the usage context is clear from the tool's purpose. It implicitly states this is the tool for retrieving the full set of materials, which is sufficient for such a straightforward operation.

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