a11y_diff_urls

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

No annotations are present, so the description must carry the burden of explaining behavior. It only states the action and the Playwright requirement; it does not disclose whether the operation is read-only, what the output looks like, or any side effects. The 'Requiere Playwright' is a prerequisite but not behavioral transparency. Thus insufficient.

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, concise sentence that states the core function and gives a concrete example. No waste, front-loaded with the primary action. It also includes the Playwright requirement.

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?

The description does not explain what the tool returns, failure conditions, or how the diff result is presented. Since there's no output schema, the agent has to guess what the call produces. The example gives some context, but the overall operational context (side effects, output format, prerequisites beyond Playwright) is missing.

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 input schema only has url_a and url_b with no descriptions Particular. The description merely says 'dos URLs' without adding meaning beyond that. It doesn't clarify order, format, or expected input conventions. With 0% schema coverage, the description should compensate but doesn't.

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 the tool snapshots two URLs and diffs them in a single call, with a concrete example (staging vs production). This is a specific verb+resource pair that distinguishes it from single-URL snapshot tools like a11y_snapshot.

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?

Provides an example use case (staging vs producción) which implies when to use, but no explicit guidance on when not to use or comparison with sibling tools like a11y_snapshot or a11y_diff. It's implied rather than explicit, so it's usable but not fully prescriptive.

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