browser_set_viewport

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

With no annotations, the description carries the full burden of behavioral disclosure. It only states the action (setting viewport size) without mentioning side effects, persistence, effect on current page, or any caveats. The recommendation of 1440x900 is a hint but not a behavioral trait.

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 extremely concise, with a single action statement and a practical recommendation. It is front-loaded and contains no unnecessary words, making it easy to scan and quickly understand.

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?

For a simple setter tool, the description is minimally adequate. It does not describe return values (no output schema), side effects, or how the change affects the browser session. Given the lack of annotations, more context about persistence or reload behavior would be helpful, but the tool's simplicity keeps this at a moderate score.

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 coverage is 0%, so the description must compensate for parameter meaning. It does not explain what width and height represent, their units, acceptable ranges, or how they interact. The phrase 'viewport size' implies the parameters correspond to dimensions, but the description adds no detail beyond the schema's property names.

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 and resource: 'Set browser viewport size.' It is unambiguous and clearly distinct from sibling tools like browser_click or browser_open. No ambiguity remains about what the tool does.

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 provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites, exclusions, or contexts where a different tool might be preferable. The only extra note is a recommended size, which is not usage guidance.

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