PickShade MCP Server

Simulate color blindness

simulate_cvd

Read-only

Show how colors look with protanopia, deuteranopia, tritanopia, and achromatopsia, and list color pairs that become hard to distinguish.

Instructions

Show how colors look with protanopia, deuteranopia, tritanopia and achromatopsia (Machado 2009 at full severity), and list the pairs that become hard to tell apart.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "colors": "<colors>"
    },
    "name": "simulate_cvd"
  }
}

Input Schema

Name	Required	Description	Default
`kinds`	No
`colors`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Oct 19, 2026

TDQS

A3.5/5.0

Behavior3/5

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

Annotations declare a read-only, closed-world operation, so the safety profile is covered. The description adds valuable specifics: Machado 2009 at full severity and the pair-confusion output. It does not mention limits on color count, encoding requirements, or the return shape, so it is adequate but not rich.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

A single front-loaded sentence that names the verb, the resources, the scientific basis, and the secondary output. No filler or repetition.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness3/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Covers the core operation and method, but with no output schema the description should say more about what is returned (simulated colors per kind, confusable pair list format) and about the colors input constraints. It is adequate rather than complete for a two-parameter simulation tool.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 0%, so the description must carry parameter meaning. It names the four CVD kinds, which maps to the kinds enum, but says nothing about the colors parameter (accepted formats, limits, required). The schema itself documents colors thoroughly, leaving the description with limited added value.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose4/5

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb and resource: simulating how colors appear under four named color-vision deficiency types, plus identifying confusable pairs. It clearly distinguishes itself from siblings like check_contrast or nearest_names, though the description leans on the technical term 'CVD' only in the tool name rather than in prose.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description implies usage (show colors under CVD and find confusable pairs) but gives no explicit when-to-use guidance or contrast against alternatives like check_contrast. An agent must infer that this is the accessibility simulation tool from the sibling list.

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

Deploy Server