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 transparently discloses the core behavior: listing materials and their associated objects. However, it does not mention edge cases like whether unused materials are included by default or how the return is structured, but for a read-only listing, the description is adequate.

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, short sentence that is concise and front-loaded with the action. It contains no unnecessary words or fluff, making it highly efficient.

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?

The tool is simple, but the parameter 'used_only' is completely unexplained, and there is no guidance on when to choose this over other material-related tools. Since an output schema exists, return values are covered, but the parameter gap and lack of usage guidance make the description incomplete.

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 0%, and the description does not explain the 'used_only' parameter. While the parameter name hints at filtering to used materials, the description adds no meaning beyond the schema's property title, leaving the agent to infer its function.

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 clearly states the tool's purpose: 'List materials and the objects that use them.' This provides a specific verb (list), resource (materials), and an additional detail (objects using them), which distinguishes it from siblings like list_lights (lights) and get_material_info (specific material info).

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 implies usage for listing materials at scene level, but it does not explicitly mention when to use this tool over alternatives like get_material_info or list_shader_nodes. No exclusions or alternative routing are provided, so guidance is only implied.

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