list_materials

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

With no annotations provided, the description carries the full burden. It clearly states a read-only action ('Return a list') with no side effects. While it doesn't discuss edge cases like an empty blend file or error conditions, the behavior is straightforward and accurately disclosed. No contradictions exist.

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, front-loaded sentence with no superfluous words. It conveys the complete purpose in a compact form, earning every word.

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, zero-parameter listing tool with an output schema present, the description is fully complete. It provides all necessary information for an agent to decide when to call it, and the output schema covers return values. No additional context is needed.

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 the schema is empty with 100% coverage. According to the rubric, a baseline of 4 applies for zero-parameter tools. The description does not need to explain parameters, and it doesn't miss anything.

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 ('Return') and resource ('a list of all material names in the blend file'), with a clear scope ('all' and 'in the blend file'). It is unambiguous and easily distinguished from sibling material tools like create_material or get_material_info because it explicitly describes a list operation.

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: an agent would naturally select this when it needs to enumerate all material names. However, there is no explicit mention of when to use this over alternatives (e.g., get_material_info for detailed info on a specific material) or any exclusions. The guidance is thus adequate but not explicit.

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