create_material

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

With no annotations, the description must carry the full burden of behavioral disclosure. It states the action but does not mention side effects (e.g., whether the material is added to the scene, assigned to an object, or set as active), any prerequisites, or what the output schema contains. The base_color format is a parameter detail, not a behavioral trait.

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 with no wasted words. It front-loads the core purpose, and the base_color clarification earns its place by resolving a potential ambiguity in parameter format.

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 simple creation tool, the description is minimal but lacks essential context: it does not explain the meaning of metallic/roughness, how the material is integrated into the scene, or what to expect from the output. The presence of an output schema is acknowledged in context signals, but its contents are undisclosed, so the definition remains incomplete.

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 has 0% parameter descriptions, so the description must compensate. It adds base_color format ('[R, G, B, A] (0-1 range)') but leaves metallic and roughness unexplained, offering no ranges or standards beyond their default values. This incomplete compensation leaves half the parameters semantically opaque.

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 'Create a new Principled BSDF material' with a specific verb and resource, and the Principled BSDF qualifier clearly distinguishes it from generic shader node creation (create_shader_node) or other material operations (list_materials, set_material_property).

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 usage context is implied by the name and description—this tool is for creating a material—but there is no explicit mention of when to prefer it over alternatives like create_shader_node or how it relates to material assignment. No exclusions or alternative tool references are given.

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