Browser Tab New

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

With no annotations, the description carries the burden of behavioral disclosure. It explicitly states that the new tab becomes active, which is a state change. However, it does not mention side effects such as how the session parameter affects behavior or any potential failures (e.g., tab limits). It covers the core mutating behavior adequately.

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, well-structured sentence with no redundant words. It front-loads the primary action and incorporates the optional navigation in a natural clause, achieving high readability and efficiency.

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 the two parameters and the existence of an output schema, the description is mostly complete for the action itself. However, it lacks any explanation of the 'session' parameter, which is relevant given sibling tools like browser_session_new. The agent may not know how to correctly use or omit the session without additional context, making it incomplete.

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 the 'url' parameter implicitly via 'optionally navigating it to a URL', but completely ignores the 'session' parameter. Since the schema provides no descriptions and the tool description only clarifies one of two parameters, the compensation is partial.

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 states a clear verb 'open a new tab', a specific resource (a tab), and a secondary action (navigate to a URL, make it active). It clearly differentiates from siblings like browser_tab_close, browser_tab_select, and browser_navigate by focusing on creation and activation.

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 usage for creating a new tab but does not explicitly contrast it with alternatives like browser_navigate (which navigates the current tab) or browser_tab_select (which selects an existing tab). No when-to-use or when-not-to-use guidance is given, leaving some inference to the agent.

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