browser_url

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

The description implies a read-only, non-destructive operation. With no annotations, this suffices for a simple getter. However, it does not disclose edge cases (e.g., behavior on empty pages or errors), so it is adequate but not thorough.

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, focused sentence with zero unnecessary words. Perfectly concise and front-loaded.

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 zero parameters, no output schema, and a simple read operation, the description provides sufficient context for the agent to understand the tool's purpose. It could mention return format (e.g., string) but is adequate.

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?

There are no parameters (schema coverage 100%), so the description adds no parameter information. Baseline 4 is appropriate since there is nothing to describe.

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's function: 'Get current page URL.' It uses a specific verb (Get) and resource (current page URL), which is unambiguous. No need for sibling differentiation due to its simplicity.

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 explicit guidance on when to use this tool versus alternatives like browser_title or browser_status. However, the purpose is singular and straightforward, so the usage context is implicitly clear. Slightly below a 4 due to lack of explicit context.

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