shading.list_materials

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

The description includes 'read-only', disclosing that the tool does not modify state. Since no annotations are provided, this is valuable. However, it does not describe other behavioral traits like return format or performance characteristics.

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 extremely concise (one sentence plus label). It front-loads the core action and read-only nature. However, it could include parameter details without significant bloat.

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 list tool, the description omits what the returned data looks like (no output schema). The agent lacks information about the structure of the material list, making it less complete for real-world use.

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 description does not mention the optional 'object' parameter, leaving the agent to rely solely on the schema which provides a title but no further context. Schema coverage is 0%, so the description should compensate but fails to do so.

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 action 'list' and the resource 'materials in the file', distinguishing it from sibling tools like 'shading.create_material' which create rather than list. However, it does not explicitly contrast with other list-type tools.

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 on when to use this tool versus alternatives. There is no mention of prerequisites, context, or when to prefer other tools (e.g., 'shading.report').

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