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

With no annotations, the description carries the full burden and does so well. It discloses side effects (saving to disk), behavior for background tabs, headless operation, the CDP dependency, and the remote-client condition for return_image. This goes well beyond the minimum.

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 front-loaded with the core behavior, followed by a concise, well-structured argument list. Every sentence adds useful information, and there is no filler or repetition of schema defaults.

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 8 parameters, no annotations, and no output schema, the description is remarkably complete. It covers capture modes, format, quality, selection targeting, filename labeling, and the return_image behavior, giving an agent everything needed 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?

Schema description coverage is 0%, but the Args block meaningfully explains all 8 parameters beyond their schema titles: url_pattern is a regex on tab URLs, full_page captures the scrollable page, quality is ignored for PNG, and return_image defaults based on remote/client context. The description fully compensates for the schema gap.

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 opens with a specific verb and resource: 'Capture a tab and save it to disk.' It also clarifies the tool's unique value versus browsing siblings by noting it works headless and for non-frontmost tabs, which sets it apart from read_tab or query_dom.

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 gives clear context on when to use it: capturing evidence, including on servers, and notes the CDP backend requirement. It does not explicitly name alternatives or exclusions, but the usage context is unambiguous enough for an agent to select this tool.

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