browser_getBounds

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

No annotations are provided, so the description carries the full burden. It states the tool retrieves position and size information, implying a read-only operation, but it does not specify return format, potential errors, or coordinate system (viewport vs. document), leaving some behavioral details undisclosed.

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 the primary action stated first and a brief explanatory clause for context. It is not verbose and contains no redundant information.

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 (one parameter, no output schema), the description provides sufficient context to understand what it does and when to use it. It lacks explicit details about the return structure, but this is not critical for basic usage.

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 already defines the 'selector' parameter as a CSS selector, covering its basic meaning. The description adds minimal extra semantic value beyond that, such as tying it to element location, which is already inferred from the tool's purpose.

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 tool retrieves element position and size, and mentions its use case for calculating click coordinates and swipe distances. This distinguishes it from sibling tools that perform actions like clicking or dragging.

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 indicates when to use the tool (for computing coordinates before actions like clicks or swipes), providing clear context. However, it does not explicitly name alternative tools or state when not to use it, so it falls short of being fully explicit.

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