check_color_contrast

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

No annotations are provided, so the description bears full burden. However, it only describes what the tool detects, not behavioral traits like whether it performs static analysis, returns results, or has any side effects. It lacks disclosure of authentication requirements or rate limits.

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 very concise at two sentences, front-loaded with the main action, and every sentence adds value. No wasted words.

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 tool with one parameter and no output schema, the description provides sufficient context about the types of issues found. However, it lacks information about the output format or return value, which would be helpful for an agent to invoke it correctly.

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?

The single parameter cssText is described in the schema with adequate detail. The description adds context about what issues are detected but does not enhance parameter meaning beyond the schema. With 100% schema coverage, baseline score is 3.

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 clearly states the tool's purpose with specific verb 'Detects' and resource 'color contrast issues in CSS'. It lists three distinct patterns it catches, which differentiates it from sibling tools like check_a11y_usage or check_dark_mode_patterns.

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 context (analyzing CSS for contrast issues) but does not explicitly state when to use this tool over alternatives like check_a11y_usage or check_dark_mode_patterns. No when-not-to-use or exclusion criteria are provided.

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