audit_responsive_visibility

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

With readOnlyHint, idempotentHint, and destructiveHint=false annotations already covering the safety profile, the description adds meaningful behavioral detail: it performs a real browser render, requires headless chromium, categorizes flags into 'likely-oversight' versus 'intentional', and returns a table with specified columns. This gives the agent a clear mental model of what will happen and what comes back.

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 three sentences with no fluff: first sentence states the action and detection mechanism, second explains the categorization, third states the output shape and a hard requirement. It front-loads the core purpose while every sentence earns its place.

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?

Despite having no output schema, the description discloses the output table columns, the distinction the tool draws, the technical prerequisite, and the operation. Combined with the annotations and fully described parameters, an agent has enough context to select and invoke the tool 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?

Schema description coverage is 100%, so the parameters URL, breakpoints, and viewportHeight are already fully documented in the schema. The description only adds that URLs are rendered at multiple breakpoints, which does not materially extend parameter understanding beyond the schema. Baseline 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 states a specific action ('flag content elements that are visible on desktop but hidden on mobile') against a specific resource (a rendered URL) and enumerates the exact CSS conditions it checks. It also distinguishes this audit from general audit siblings by naming the hidden-on-mobile content bug it targets.

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 makes the intended use case explicit: auditing a URL across breakpoints for content that disappears on mobile, with a clear environment prerequisite (headless chromium). It does not explicitly name sibling alternatives or say when not to use the tool, but the use case is specific enough that an agent can recognize when it applies.

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