Select objects in Rhino by their display color. Provide an RGB string like '255,0,0' to pick all matching objects.
Select objects by display color.
Args:
color_rgb: Comma-separated RGB string, e.g. '255,0,0' for red.
| Name | Required | Description | Default |
|---|---|---|---|
| color_rgb | No | 255,0,0 |
| Name | Required | Description | Default |
|---|---|---|---|
| result | Yes |
Changes observed during successful MCP inspections.
v1.0.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations, the description carries the full burden of behavioral disclosure. It states the selection criterion but does not reveal important behavior such as whether the current selection is replaced or added to, whether hidden/locked objects are included, or how display color is determined. This is a significant gap for a selection-modifying operation.
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 extremely concise: one clear sentence plus a parameter explanation. Every line earns its place, and the essential information is front-loaded. No filler or redundancy.
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 one-parameter tool with an output schema, the description covers the basic purpose and parameter format. However, it omits usage guidance and key behavioral details about selection semantics, making it only minimally adequate for an agent to fully understand the tool's side effects.
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%, so the description must compensate. It fully explains the only parameter: 'Comma-separated RGB string, e.g. '255,0,0' for red.' This provides the format, example, and meaning, which the schema itself lacks.
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 verb and resource: 'Select objects by display color.' This clearly identifies the tool's function and the selection criterion, distinguishing it from siblings like sel_by_name or sel_by_type, although it does not explicitly name them.
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: use this when you need to select objects by their display color. However, it offers no guidance on when to prefer this over alternative selection methods (e.g., by name, type, layer) and no exclusions or prerequisites.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.