Resize page

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

The description discloses that it moves the actual OS window and clarifies that it does not affect device pixel ratio, mobile flag, or touch—those belong to emulation. This adds meaningful context beyond the readOnlyHint, idempotentHint, and destructiveHint annotations, with no contradiction.

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, each adding distinct value: the action, the use case, and the alternative for viewport emulation. There is no redundancy or unnecessary detail.

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 two-parameter tool with full schema coverage and an output schema, the description fully covers the functionality, its purpose, and its limitations. It is self-contained and complete for an agent to invoke 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 coverage is 100% with both width and height clearly described in CSS pixels. The description adds no extra parameter-specific meaning beyond what the schema already provides, so the baseline score of 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 clearly states the action ('Resize the browser window') and the target resource, distinguishing it from viewport emulation tools like emulate and emulate_device. The verb is specific and the scope is unambiguous.

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?

Explicitly explains when to use this tool (responsive-layout checks requiring accurate screenshots) and provides direct alternatives for viewport-only emulation (emulate's viewport parameter or emulate_device). This gives clear when-to-use and when-not-to-use guidance.

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