create_material

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

No annotations are provided, so the description carries the full burden. It mentions 'or replace' hinting at upsert behavior, and 'auto-assign this material to (slot 0)' giving some context, but it does not explain side effects of replacing existing materials, error conditions, or permissions needed. The behavioral description is minimal.

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 one clear sentence followed by a well-structured list of parameters. It is front-loaded with the purpose. Slightly verbose but efficient overall.

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 tool with 8 parameters and no output schema, the description covers parameters well but lacks information about return values, error handling, or what happens on replacement. It does not explain the 'assign_to' behavior in depth. Adequate but not complete.

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 schema description coverage is 0%, meaning the description is the sole source of parameter semantics. It provides detailed information for all 8 parameters, including ranges, defaults, and format (e.g., 'Comma-separated r,g,b in 0..1'). This adds significant value beyond the input schema's titles and defaults.

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 starts with 'Create (or replace) a PBR material using Principled BSDF', clearly stating the verb (create/replace) and resource (PBR material). This distinguishes it from sibling tools like 'assign_material' (which applies existing materials) and 'set_object_material_color' (which only changes color).

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 the tool is for creating or replacing materials, but it does not explicitly state when to use it vs alternatives like 'assign_material' or when to set material properties directly. No when-not-to-use guidance is provided.

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