set_principled_bsdf

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

No annotations are provided, so the description must convey behavioral traits. It states value ranges for colors and scalars but omits critical details: whether the tool creates a new material, modifies an existing one, or if it requires the object to already have a Principled BSDF node. Side effects like overwriting existing node setups are not disclosed.

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 two sentences, front-loaded with purpose, and provides essential formatting rules without extraneous information. Every word serves a purpose.

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 15 parameters and no output schema, the description is too brief. It lacks context on how the tool interacts with objects and materials, such as whether it creates a new material or modifies an existing one, and what happens if the material does not have a Principled BSDF node.

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 partially compensates by specifying that colors are arrays [R,G,B] or [R,G,B,A] in 0-1 range and scalars are 0-1 except emission_strength and ior. However, it does not explain the object_name or material_name parameters, leaving some parameters semantically bare.

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 'Full control over Principled BSDF PBR shader', indicating the tool modifies a specific shader. It distinguishes from sibling tools like set_material or set_material_color by focusing on Principled BSDF parameters, but does not explicitly contrast with other material creation 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?

The description says 'Only set the parameters you need', implying partial updates, but does not specify when to use this tool versus alternatives like set_material_color or material_create_pbr. No exclusions or prerequisites are given.

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