create_material

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

With no annotations, the description carries the transparency burden. It discloses that this is a write operation that creates a material in /mat, which is core behavior. It does not mention collision/overwrite behavior, whether a material network is required, or what the tool returns, leaving some behavioral ambiguity.

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 front-loaded with a one-line summary and follows with a compact Args block. Every line adds needed value, and there is no filler or repetition of schema defaults beyond useful constraints.

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 no-annotation tool with no output schema, the description is sufficient to invoke correctly, but it is not fully complete: it omits usage alternatives, side effects, and any expected return/confirmation. Missing context is not severe because the parameter semantics are fully covered.

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%, but the description compensates fully by documenting all six parameters: name semantics, valid mat_type values ('principled', 'materialx'), base_color format and range, and roughness/metallic/opacity ranges. This goes well beyond the bare input schema.

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 names a specific action ('Create'), resource ('material'), and location ('/mat'), and adds that surface properties are configurable. It is clear enough to separate creation from read-only material tools like list_materials/get_material_info, though it does not explicitly distinguish itself from the sibling create_material_network or assign_material.

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 context is implied: use this when you need to create a new material node in /mat. However, it does not state when to prefer assign_material, create_material_network, or list_material_types, and there are no explicit exclusions or alternative routing.

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