open_page

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 discloses key behavior beyond the mere action: it waits for bridge connection and returns a page ready for capture. This gives the agent useful operational expectations, though it doesn't mention timeout behavior or what happens if the browser isn't available.

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?

Two sentences, directly front-loaded with the action, and every clause adds value: what it opens, where it navigates, and what it waits for. No filler or redundancy.

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 single-parameter tool with no output schema, the description provides essential context: it creates an instrumented tab, waits for connectivity, and returns a ready-to-capture page. It could be slightly more complete by stating a prerequisite (e.g., 'requires a controlled browser already launched'), but the current text is sufficient for most correct 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 fully describes the only parameter with 'URL to open.' The description adds contextual phrasing ('navigate it to a URL') but no additional semantic detail, format requirements, or edge-case guidance. With 100% schema coverage, the baseline 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 uses a specific verb and resource: 'Open a new instrumented tab in the controlled browser and navigate it to a URL.' It also adds the outcome ('returns it ready to capture'), which distinguishes it from sibling tools like list_pages or screenshot_page. The scope and intent are immediately clear.

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 when to use this tool: after a controlled browser exists, to create a fresh page for subsequent capture. It clearly sets context by saying 'in the controlled browser' and 'ready to capture.' It doesn't explicitly name alternatives or state when not to use it, so it falls short of a full 5.

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