colors_scaleGenerate perceptually uniform color scales from two or more input colors, interpolating in a chosen color space with configurable steps for frontend design.
Generate a perceptually uniform color scale
| Name | Required | Description | Default |
|---|---|---|---|
| mode | No | Interpolation color space (default: oklch) | oklch |
| steps | No | Number of steps to generate (max 20) | |
| colors | Yes | List of colors to generate scale from |
Changes observed during successful MCP inspections.
v1.1.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile needs no restating. The description adds only 'perceptually uniform', which hints at interpolation quality but is not explained. It says nothing about how the scale is ordered, how endpoints are treated, or determinism beyond what idempotentHint already implies.
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 front-loaded sentence with no filler or redundancy. It is efficient, though the terseness edges into under-specification rather than maximal usefulness.
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?
The input schema is fully documented and annotations cover safety and idempotency, so the minimum an agent needs to call the tool is present. But for a generator that overlaps heavily with colors_mix and colors_adjust, the definition leaves the selection decision and the nature of the output ('perceptually uniform' in which space when mode changes) unexplained.
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 100%: each of the three parameters (colors, steps, mode) has a description, defaults, bounds, and an enum for mode. The description adds nothing beyond the schema, which is the expected baseline when the schema does the heavy lifting.
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 gives a clear verb+resource ('Generate a ... color scale') and adds the distinguishing quality 'perceptually uniform'. However, it is nearly a verbatim restatement of the title and offers no differentiation from siblings like colors_mix, colors_adjust, or colors_convert, which also produce or manipulate colors. An agent cannot tell from this text alone which sibling applies to a given request.
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?
There is no guidance on when to use this tool versus colors_mix (which also interpolates between colors) or colors_adjust. No prerequisites, no exclusions, no alternative named. The agent must infer usage entirely from the tool name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.