tab_new

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

With no annotations, the description adds 'Automatically switches to the new tab' but lacks details on what happens to the previous tab, output format, or whether URL validation occurs.

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?

Two concise, front-loaded sentences with no redundant information. Every phrase adds value.

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 opening a tab and automatic switching. Minor omission: no mention of URL requirements (absolute, special URLs) or error conditions.

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 description adds meaning to the 'url' parameter by stating it's optional and used for navigation, compensating for zero schema coverage. However, no format or default behavior (e.g., blank tab) is specified.

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 specific action: opening a new browser tab with optional URL navigation. It distinguishes from sibling tools like tab_find (find existing tabs) and page_navigate (navigate 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?

No guidance on when to use this tool vs alternatives (e.g., page_navigate, tab_find). The automatic switch behavior is implied but not explicitly contrasted with other tab operations.

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