set_viewport

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

With no annotations provided, the description explains parameters (CSS pixels, DPR, mobile toggle) but does not disclose side effects (e.g., overriding previous viewport settings, requiring an active browser). It provides basic transparency but lacks deeper behavioral context.

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, with no wasted words. The use of backticks for parameter names is clear, though the formatting could be slightly cleaner. Overall efficient.

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 tool's simplicity (4 parameters, no nested objects) and the presence of an output schema (not shown), the description covers essential behavioral details. It does not mention prerequisites (e.g., browser must be running) but is otherwise sufficient for an agent to use 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%, so the description bears the full burden. It adds meaning to all four parameters: width/height in CSS pixels, device_scale_factor as DPR, mobile toggles meta-viewport/overlay-scrollbar. This significantly compensates for missing schema descriptions.

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 uses a specific verb 'Override' and resource 'visible viewport dimensions', clearly distinguishing it from sibling tools like set_device (which sets device metrics including viewport) and restore_viewport (which reverts).

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?

No explicit guidance on when to use this tool vs alternatives such as set_device or restore_viewport. The description does not mention when to use or not use this tool, nor does it give context for prerequisites.

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