open_new_tab

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It clearly states the core action and optional URL navigation, but it does not disclose whether the new tab becomes the active tab, whether a handle is returned, or any side effects beyond opening the tab.

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?

A single, front-loaded sentence states the action and the one modifier. Every word earns its place, with no redundant filler or restatement of the tool name.

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 tool with one optional parameter and no output schema, the description is largely sufficient. It covers the action and the parameter's role, though it could be slightly more complete by noting what happens when no URL is provided or whether the new tab receives focus.

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 100%, and the schema already documents url as optional. The description adds the behavioral context that the URL is used for navigation, but it does not add meaningful detail beyond what the schema already conveys.

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 ('Open') and a clear resource ('new browser tab'), and adds the optional navigation behavior. The word 'new' distinguishes it from sibling tools like navigate, which operate on the current 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 phrase 'new browser tab' implies this tool is for opening a separate tab rather than navigating the current one, and 'navigate' exists as a sibling. However, there is no explicit statement about when to choose this over navigate or start_browser, nor any prerequisites such as an already-running browser session.

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