list_materials

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

With no annotations, the description must disclose all behavioral traits. It only says 'List all material nodes under a root path' and provides no information about side effects (whether read-only), return format, error behavior, or performance. It does not even state that it is a read operation, leaving the agent to infer safety. This is a significant gap for a tool with zero annotation coverage.

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: the main purpose appears in the first sentence, and the Args section is clearly structured. There is no redundant text. However, it is under-specified, which is a content issue rather than a conciseness issue; the structure itself is 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 (list materials under a path), but the description lacks essential context: it does not specify the return value (list of paths? names? objects?), whether the result is ordered, or what happens when no materials are found. With no output schema and no annotations, the agent is left with minimal information to interpret results or handle edge cases. The description is incomplete for reliable invocation.

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%, so the description must compensate. It defines root_path as 'Root path to search for materials,' which adds basic meaning beyond the schema's name, but it does not explain the expected format (e.g., Houdini path syntax), whether wildcards are allowed, or how the default '/mat' is used. The mention of 'ctx' in Args is also not in the schema, adding ambiguity. The description provides minimal semantic value.

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 clear verb+resource: 'List all material nodes under a root path.' This distinguishes it from create_material (creation) and assign_material (assignment), and from get_material_info (querying a specific material). However, it does not explicitly contrast with other listing tools like list_material_types or get_usd_materials, so it lacks explicit sibling differentiation.

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?

No guidance is given on when to use this tool versus alternatives. The description does not mention any conditions, prerequisites, or exclusions, nor does it reference sibling tools. An agent has no information about when this tool is preferred over other listing options.

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