create_principled_material

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

With no annotations provided, the description carries full burden. It discloses all parameters, defaults, and ranges, and states the return format. However, it does not mention side effects (e.g., whether it replaces an existing material, whether it is added to a specific object, or if it requires an active object). Basic transparency is present but missing behavioral context beyond the parameters.

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 structured as a concise docstring with first-line summary, Args section, and Returns section. While the Args list repeats parameter information already in the schema, it is justified given 0% schema coverage. The first sentence effectively front-loads the purpose. Minor redundancy with schema titles is acceptable.

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?

Given the tool has 10 parameters, no annotations, but an output schema, the description explains all parameters and return format. However, it omits important context such as whether the material is automatically assigned to an object, whether it replaces existing materials, or if there are prerequisites like an active mesh object. This leaves the agent needing to infer missing usage requirements.

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 systematically lists each parameter with default values, ranges, and semantic explanations (e.g., 'metallic: Metallic value 0.0-1.0', 'transmission: Transmission weight'). This adds meaning beyond the schema titles and types, though could be slightly more explicit about the color list format (e.g., RGBA values between 0 and 1).

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 'Create a fully configured Principled BSDF material in one call,' using a specific verb (create) and resource (Principled BSDF material). Among sibling tools like 'create_material', this distinguishes itself by specifying the shader model and the 'fully configured' aspect.

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 creating a Principled BSDF material but does not explicitly state when to use this tool versus alternatives like 'create_material' or 'assign_material'. No when-not-to-use guidance or context about prerequisites (e.g., needing an active object with a material slot) is provided.

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