Resize the browser viewport to specified pixel dimensions and capture a snapshot to verify the new layout.
Resize the browser viewport to the given width and height, then return a snapshot.
| Name | Required | Description | Default |
|---|---|---|---|
| width | Yes | Viewport width in pixels. | |
| height | Yes | Viewport height in pixels. |
Changes observed during successful MCP inspections.
v0.1.0Does 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 does state the core behavior and that a snapshot is returned, but it does not mention side effects, whether the resize persists, or what the snapshot contains. This is adequate but not rich.
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?
A single sentence with no filler. The primary action is front-loaded, and the return behavior is included efficiently. Every word earns its place.
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 tool with two fully documented parameters and no output schema, the description is mostly complete: it states the action and that a snapshot is returned. It could clarify what 'snapshot' means, but this is a minor gap given the tool's simplicity.
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 100%, so the schema already documents width and height as pixel values. The description only refers to them as 'given width and height' and adds no additional semantic detail beyond the schema.
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 verb ('Resize'), a clear resource ('browser viewport'), and the exact inputs ('given width and height'). It also adds a secondary behavior ('return a snapshot'), which distinguishes it from other browser tools that do not resize the viewport.
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 given about when to use this tool versus alternatives such as browser_snapshot or browser_take_screenshot. The description explains what it does but not the conditions under which an agent should choose it over siblings.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.