browser_new_tab

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 only states it opens and switches, but fails to mention what happens if no URL is provided (e.g., opens a blank tab), whether the operation can fail, or any side effects like closing existing tabs. The description is too sparse to inform the agent of behavioral traits.

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 very concise at one sentence, which is appropriate for a simple tool. However, it could be slightly more informative without adding significant length, e.g., by mentioning the optional nature of the URL or the effect of omitting it.

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 tool's simplicity (one optional parameter, no output schema), the description provides the basic functionality but lacks completeness. It omits details like the behavior when url is omitted, whether the tab is focused, and how it relates to sibling tools like browser_switch_tab. With zero annotations, more behavioral context would improve completeness.

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% (the 'url' parameter has a description: 'URL to navigate to in the new tab'). The tool description adds no additional meaning beyond the schema, so a baseline score of 3 is appropriate. It does not clarify whether the parameter is optional or required, but the schema implies optional via absence of required array.

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 tool's purpose: 'Open a new browser tab and switch to it.' It specifies the action (open and switch) and the resource (browser tab), effectively distinguishing it from sibling tools like browser_switch_tab (which switches to an existing tab) and browser_navigate (which navigates 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 description provides no guidance on when to use this tool versus alternatives. With 18 sibling tools, including browser_switch_tab and browser_navigate, there is no mention of when to choose this over them, nor any indication of prerequisites or conditions.

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