browser_set_viewport_size

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

The description only states the action without disclosing any side effects, such as whether it triggers a resize event, reloads the page, or persists across navigations. With no annotations provided, the description should carry this burden but doesn't.

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 words and contains zero redundant information. It is appropriately sized for a simple setter action.

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 viewport setter, the basic action is clear, but the description lacks context about its effect on the current page, relation to browser_resize, or whether navigation is needed. It's minimally complete but misses behavioral context.

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 schema comprehensively describes both width and height parameters with units (pixels), and the description adds no additional parameter semantics. Baseline of 3 is appropriate given 100% schema coverage.

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 clearly states the action 'Set viewport size' with a specific verb and resource. It is unambiguous but doesn't explicitly distinguish from the sibling tool browser_resize, so it's not a perfect 5.

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 guidance is provided on when to use this tool versus alternatives like browser_resize, nor any context such as before/after navigation. The description gives no usage context.

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