browser_new_tab

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

No annotations are provided, so the description carries full responsibility for behavioral disclosure. It states the return value (targetId) but does not explain whether the new tab becomes active, whether it opens in the background, what happens with invalid URLs, or any side effects on the current tab. For a tool with no annotation coverage, this is insufficient.

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?

A single, direct sentence with no filler. The key action and return value are front-loaded. Optimal length for a simple tool.

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 is simple (one optional parameter, no output schema, no annotations), the description is minimally adequate. It states the action and the return. However, it lacks context on how the new tab interacts with the existing browsing session (e.g., does it become active? is it added to the tab list?). For an agent that needs to manage multiple tabs, this is a notable gap.

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% – the 'url' parameter has no description in the schema. The description does not mention the parameter at all, leaving the agent to infer that 'url' is the address to open. Since it is optional and defaults to 'about:blank', the agent might not know the meaning or format expected. The description adds no value beyond the schema.

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?

States a specific verb 'Open' and resource 'a new browser tab'. Clearly distinguishes from sibling tools like browser_goto (which navigates existing tab) and browser_switch_tab (which switches to an existing tab). The purpose is unambiguous.

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 the tool is for creating a new tab, but does not explicitly state when to use it versus alternatives (e.g., when you want to keep the current tab intact). It does not mention that this is the tool to use for a fresh browsing context or that it should be used when you need a separate targetId for later operations.

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