rhino_material_assign

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

Annotations already declare readOnlyHint=false, so the mutation aspect is covered. The description adds mild context by specifying the material must be 'existing' and that the operation applies to 'one or more objects,' implying batch behavior, but it does not disclose whether prior material assignments are replaced or what happens on invalid inputs.

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?

A single concise sentence that states the action, resource, and scope with no redundant words. It earns its place entirely.

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 assignment tool, the description plus schema constraints and mutation annotation are mostly sufficient: doc_id is documented in the schema, object_ids constraints are present, and the description clarifies the operation's purpose. It would be more complete if it noted that the material must already be defined (beyond the word 'existing') or differentiated from sibling material tools, but nothing critical is missing.

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% for the top-level args, so the description must help interpret parameters. It does map to the key parameters: 'existing material' corresponds to material_name and 'one or more objects' to object_ids, but it does not explain doc_id or provide explicit parameter-level guidance beyond what the schema already offers for doc_id.

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 ('Assign') and identifies both the resource ('existing material') and target ('one or more objects'), clearly stating the action. However, it does not distinguish this tool from similarly named siblings like rhino_assign_material_to_object or rhino_set_object_material, so it stops short of full differentiation.

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 no guidance on when to prefer this tool over alternatives, and no exclusions or prerequisites are stated. With multiple material-related siblings (rhino_assign_material_to_object, rhino_set_object_material, rhino_layer_set_material), an agent cannot determine which one to select for a given task from the description alone.

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