Get current URL

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

No annotations are provided, so the description must carry the full burden of behavioral disclosure. It only states 'Return the current page URL' without mentioning that it is read-only, what happens if no page is loaded, or that it doesn't affect browser state. This is essentially a restatement of the title with no added behavioral context.

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 a single, minimal sentence with no redundant wording or filler. It is appropriately sized for such a simple tool.

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 getter with no parameters and no output schema, the description covers the essential purpose. It omits potential error behavior and return format, but given the tool's simplicity, it remains reasonably complete.

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 tool has zero parameters, and schema description coverage is trivially 100%. Per the rubric, a baseline of 4 is appropriate for tools with no parameters; the description correctly implies no arguments are required.

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?

Description uses the specific verb 'Return' with resource 'current page URL', clearly identifying the tool's function. This distinguishes it from siblings like browser_navigate (which changes the URL) and browser_get_text (which retrieves text content).

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 implies the tool is used when the current URL is needed, but it provides no explicit guidance on when to use it versus alternatives, nor any exclusions. With sibling tools like browser_navigate, the contrast is implicit but not stated.

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