material_list

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the description's '[INSPECT] Read-only' largely restates structured data. It does add return-field information (type, color, transparency), which is useful since no output schema exists, but provides no behavioral detail like pagination, scene-size limits, or instance scoping.

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?

Two short lines with zero waste and the scope statement front-loaded. Nothing redundant or padded.

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?

With no parameters, no output schema, and safety fully covered by annotations, the description supplies the essential returned fields so an agent knows what it gets back. It stops short of describing list ordering or whether instanced/derived materials are included, but is otherwise complete for a simple enumeration tool.

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 takes zero parameters, so per the baseline this is a 4. Nothing in the schema needs semantic elaboration, and the description appropriately does not invent parameter guidance.

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?

States a specific verb+resource ('All materials in the scene') and clarifies scope with the returned attributes. It implicitly separates itself from material_details (single-material lookup), but never names that sibling or draw the contrast explicitly.

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 '[INSPECT] Read-only' tag implies a safe inspection context, but there is no explicit guidance on when to call this versus material_details, shader_list, or texture_list. Usage is left to inference from the name.

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