browser_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 states 'Open a new tab' but does not disclose whether the new tab becomes active or focused, whether it returns a tab identifier, or what happens if the URL is invalid. These are significant behavioral aspects for a browser automation tool, and their absence leaves the agent guessing.

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, efficient sentence with no filler. The core action is front-loaded, and the optional parameter is mentioned succinctly. It earns its place without 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?

The tool is simple with one optional parameter and no output schema, so the description might seem adequate. However, it omits critical context about tab focus/activation, which is directly relevant given the sibling browser_switch_tab tool. The lack of any behavioral disclosure beyond the bare action leaves the agent uncertain about the tool's side effects, making the description incomplete for safe and 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?

The schema has one parameter (url) with no description, and schema description coverage is 0%. The tool description says 'optionally with a URL,' which clarifies that the url parameter is optional and indicates its purpose. This adds some meaning beyond the raw schema, but it does not elaborate on URL format, default behavior when omitted, or interaction with existing tabs.

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 resource ('a new tab'), clearly indicating the tool's core action. It also mentions the optional URL parameter, which adds specificity. However, it does not explicitly differentiate from sibling tools like browser_open or browser_switch_tab, though the name itself implies a distinct action.

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?

There is no guidance on when to use this tool versus alternatives such as browser_open (which might open a URL in the current tab) or browser_switch_tab. The description does not state any prerequisites, exclusions, or scenarios where this tool is preferred. It leaves the agent to infer usage from the name alone.

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