ap_material_assign

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

With no annotations, the description carries the behavioral disclosure burden. It does disclose that the operation assigns an existing material and that lookup is by name, which is useful. However, it does not mention what happens if the object or material does not exist, whether the assignment replaces an existing material, or any side effects.

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?

Two concise sentences with no redundant wording. The primary operation is front-loaded, and the important lookup detail about material naming is placed second.

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 two-parameter mutation tool, the description covers the core operation, the lookup mechanism, and the material naming convention. It is slightly incomplete around failure behavior and return values, but those are minor for this tool's simplicity.

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 input schema already documents both parameters with 100% coverage, providing the baseline of 3. The description adds meaningful naming semantics beyond the schema by clarifying that the material name is the node-canvas name, which is essential for correct invocation.

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 uses a specific verb and resource: 'Assign an existing material to a scene object.' It clearly distinguishes this from sibling tools like ap_material_create, ap_material_select, and ap_material_delete by focusing on assignment to an object rather than creation, selection, or deletion.

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 gives practical context by explaining that both object and material are looked up by name, and that a material's name is its node-canvas name as reported by ap_material_get_active. This helps an agent know exactly how to supply the material argument, though it does not explicitly list when not to use the tool versus alternatives.

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