browser_open

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

Annotations already signal this is not read-only and may have external effects. The description adds useful context about creating an 'owned tab' and echoing back the hint, but it does not disclose details like behavior when the URL fails, whether the current tab changes, or session implications. Acceptable 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?

Two tightly written sentences. The first front-loads the core behavior, and the second adds targeted guidance on `hint` without wasting words. Every sentence 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 open action with an output schema and annotations, the core behavior is covered. However, the description omits the `session` parameter semantics and does not clarify how this relates to the sibling tools, so an agent may still have unanswered questions about multi-tab or multi-session workflows.

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 0%, so the description must compensate. It explains `hint` well but says nothing about `url` or `session`. The `url` is required and only typed as string; the description does not add format, protocol, or usage guidance. Only one of three parameters gains real semantic value from the text.

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?

States a specific verb and resource: 'Open a URL in a new owned tab and return the element table.' This clearly distinguishes it from sibling tools like browser_tabs or browser_observe by emphasizing the new owned tab and the returned element table.

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 makes clear this is the entry action for opening a URL and gives specific guidance for using the `hint` parameter. It does not explicitly name alternatives or exclusions, but the open-and-return-table purpose is unambiguous enough for an agent to select it.

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