check_contrast

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

No annotations provided, so description must disclose all behavioral traits. It mentions supported color formats and WCAG levels but fails to specify output (ratio/pass-fail), alpha channel handling, or limitations.

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?

Two sentences, concise and to the point. Could benefit from a bit more structure (e.g., listing output format) but no filler.

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?

With 4 parameters, no output schema, and no annotations, the description is incomplete. It lacks explanation of what the tool returns, how to interpret results, or edge cases (e.g., invalid colors).

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 coverage is 100%, so baseline 3. Description adds context by mentioning supported color formats (hex, rgb, named), going beyond the schema's 'string' type. However, it does not elaborate on the distinction between foreground and background.

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?

Description clearly states it checks color contrast ratio for WCAG compliance, and specifies supported color formats. This sets it apart from broader accessibility tools like analyze_accessibility.

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 use for contrast checking but does not explicitly guide when to use this tool over siblings like analyze_accessibility or generate_accessibility_report.

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