rhino_set_color

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

Annotations indicate readOnlyHint=false, destructiveHint=false, and idempotentHint=true, which already convey that this is a harmless, idempotent write operation. The description does not add behavioral context beyond the annotations—it does not mention any side effects, scope limitations, or that it only affects visual display rather than geometry or materials.

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 a single clear sentence with no unnecessary words, which is appropriate for a simple tool. It is efficient, though it could benefit from a bit more context without becoming verbose.

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?

While the tool is straightforward, the description does not explicitly state that the color is the display color (as opposed to material color) or that multiple objects are targeted via GUIDs. The schema covers the GUID requirement and RGBA semantics, so the missing context is minor but still a gap for an agent that only reads the description first.

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 description does not mention any parameters, but the input schema provides comprehensive descriptions for the nested Color object (r, g, b, a each with range explanations) and the guids field ('GUIDs of objects'). The schema alone is sufficient for an agent to understand what values to supply, so the lack of parameter info in the description is compensated by the 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 states a specific action ('Set') and resource ('display color') on objects, making the primary purpose clear. However, it does not distinguish this tool from similar sibling tools like rhino_set_layer_color or rhino_set_material, so while the verb and resource are explicit, the differentiation is left to the name.

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 provides no guidance on when to use this tool versus alternatives. It does not mention any context, prerequisites, or exclusions, leaving the agent to infer that it is the right choice among the many 'rhino_set_*' siblings.

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