open_url

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It transparently explains that navigation happens through CDP, the window is not raised, and beforeunload handling defaults to dismiss with a lab-mode exception. It also exposes the escape hatches for controlling that behavior, which is valuable beyond the schema.

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 compact and front-loaded: the core purpose is stated first, followed by the important behavioral caveat and the available control options. Every clause adds information, and there is no redundant filler.

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?

An output schema exists, so return-value documentation is not required. The description covers the main action, the unusual no-window-raise behavior, and the nuanced beforeunload handling. It could be more complete by explicitly routing to alternatives like open_new_tab and clarifying session_id, but overall it provides enough context for correct invocation.

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 does meaningfully explain beforeunload and intent_leave, which are the most semantically tricky parameters. However, url, timeout, and session_id receive no explanation, leaving a partial gap for a five-parameter tool.

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 action: navigate the current real-browser tab via CDP, without raising its window. It uses a specific verb and resource, and the phrase 'current real-browser tab' distinguishes it from sibling tools like open_new_tab or switch_tab.

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 this tool operates on the existing current tab, which suggests it is for navigation rather than opening new tabs. However, it never explicitly contrasts it with open_new_tab or states when to choose this tool over alternatives. The 'use accept/manual/intent_leave' guidance concerns parameter behavior, not tool selection.

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