browser_new_tab

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

With no annotations, the description carries the full burden of disclosing behavior. It states the core action and the optional URL navigation, but it does not mention whether the new tab becomes active/focused or what happens when URL is omitted. This is a meaningful but minor gap for a simple browser tool.

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 compact sentence that front-loads the primary action ('Open a new tab') and then adds the optional behavior. Every word earns its place, with no redundancy or 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?

For a simple one-parameter tool with an output schema, the description covers the core invocation and the optional argument. It is sufficiently complete to select and call the tool, though slightly more context about tab-activation behavior would make it fully self-contained.

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%, so the schema already documents the url parameter as 'URL to open (optional)'. The tool description adds no substantial meaning beyond that, so the baseline score of 3 is appropriate.

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 names a specific action ('Open a new tab') and a clear resource, with the navigation behavior as optional. It is immediately distinguishable from sibling tools like browser_navigate, browser_switch_tab, and browser_close_tab because it centers on creating a new 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 gives clear context for what the tool does, but it does not explicitly say when to use it instead of browser_navigate or browser_switch_tab, nor does it mention any exclusion criteria. Usage guidance is implied by the tool name and the phrase 'new tab' but is not made explicit.

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