check_contrastCheck the WCAG contrast ratio between a foreground and background color, with AA/AAA pass/fail for normal and large text.
| Name | Required | Description | Default |
|---|---|---|---|
| bg | Yes | Background color (hex, rgb(), or hsl()). | |
| fg | Yes | Foreground color (hex, rgb(), or hsl()). |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=true and idempotentHint=true, so the safety profile is clear. The description adds valuable behavioral detail about AA/AAA pass/fail evaluation for normal and large text, which goes beyond the basic 'check' verb. It doesn't mention return format or error handling, but the annotations lower the bar for this dimension.
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 sentence that is front-loaded with the core action and outcome. There is no redundant phrasing, and every part contributes meaning.
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 simple two-parameter tool with good annotations and full schema coverage, the description adequately covers the tool's purpose and key outputs (AA/AAA for normal/large text). It does not describe the exact return structure, but no output schema exists, and the description mentions the essential result criteria.
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%: both fg and bg are described as color strings with acceptable formats. The description does not add extra parameter semantics beyond what the schema already provides, so the baseline score of 3 is appropriate.
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 uses a specific verb ('Check') and names the exact resource ('WCAG contrast ratio between a foreground and background color'), making the tool's purpose immediately clear. It also distinguishes itself from sibling tools like extract_colors or get_palette by focusing on contrast checking rather than color extraction or palette generation.
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 clearly implies when to use the tool: whenever you need to evaluate contrast between two colors against WCAG standards. However, it does not explicitly mention alternatives or situations when not to use it, missing the top tier of guidance.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
Add one secure layer between your agents and this server.
Each tool targets a distinct operation within the color, font, or code utility domains. Descriptions clearly differentiate retrieval, search, and action tools, so an agent can reliably select the right one without ambiguity.
All names use snake_case and are readable, but there's a mix of direct verb_noun patterns (check_contrast, extract_colors) and a get_ prefix for retrieval tools (get_font, get_palette). The inconsistency is minor and the pattern remains predictable overall.
15 tools is at the upper end of the well-scoped range, but each tool serves a clear, distinct purpose across three focused domains (fonts, colors, code). No tool feels redundant or unnecessary for the server's mission.
The server provides a comprehensive lifecycle for its domains: font search, metadata, file access, CSS generation, and image recognition; color extraction, naming, shading, contrast checking, and palette search; and code detection, conversion, and minification. No obvious gaps exist.