set_object_material_color

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

With no annotations, the description carries full burden. It discloses that it creates the material if needed, which is important. However, it does not mention potential side effects like overwriting existing color, error handling for invalid indices, or undo behavior. It is adequate but not exhaustive.

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 concise: two sentences plus a parameter list. No unnecessary words. Front-loaded with the core action and key behavior. Efficient.

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 the simplicity of the tool and lack of output schema, the description covers purpose, parameter semantics, and the notable behavior of material creation. It lacks some edge-case details (e.g., out-of-range index) but is sufficient for a straightforward setter tool.

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 coverage is 0%, so description must compensate. It explicitly states the range for r, g, b, a (0..1) and explains material_index as 'which material slot to update', adding meaning beyond the schema. It does not explain 'name' but it is clear from context.

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 the verb 'Set' and the resource 'Principled BSDF base colour of an object's material', which is specific. It also mentions that it creates the material if one does not exist, differentiating it from siblings like 'assign_material' or 'set_face_material_index'.

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 implies usage for setting material color, but does not provide explicit when-to-use or when-not-to-use guidance, nor does it compare with sibling tools. The context is clear but lacks exclusionary language.

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