check_url_accessibility

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

No annotations are provided, so the description must disclose behavioral traits. It describes the tool as performing checks, which implies read-only behavior, but it does not explicitly confirm non-destructiveness or mention any potential side effects, rate limits, or prerequisites.

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 concise and well-structured, with a front-loaded purpose, a bullet list of checks, and clear Args/Returns sections. Every sentence adds value without redundancy.

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 existence of an output schema for return values, the description adequately covers input and behavior. It could be improved by noting it covers multiple rules comprehensively, but it is largely complete for a single-parameter tool.

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 schema has 0% coverage for the 'url' parameter. The description compensates fully by explaining 'URL to test' and providing an example format ('https://example.com'), adding clear semantic value beyond the schema.

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 it performs automatic WCAG 2.1 AA accessibility checks for a URL, listing specific checks like image alt texts, headings, etc. It distinguishes from sibling tools that are more specific (e.g., check_color_contrast) by being comprehensive.

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 this tool is for a full accessibility check but does not explicitly state when to use it vs. sibling tools. No guidance on exclusions or alternatives, leaving the agent to infer from context.

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