zen_new_tab

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

With no annotations, the description must fully disclose behavior. It only states that a new tab is opened and an optional URL can be provided. Missing details: whether the new tab becomes active, what happens if the URL is invalid, whether it requires user permissions, or any side effects on current tabs. This is minimal behavioral disclosure.

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 two sentences, using a clear 'Args:' structure for parameter documentation. Every element is useful, though it could be slightly more structured (e.g., bullet points) to improve readability. No wasted words.

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 tool with one optional parameter and no output schema, the description covers the basic functionality adequately. However, it lacks information about what the tool returns (e.g., tab ID), edge cases (e.g., max tabs limit), and how it integrates with other tab management tools. It is minimally complete but leaves gaps.

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 coverage is 0%, meaning the schema provides no parameter descriptions. The description compensates by explaining the 'url' parameter: 'URL to open in the new tab (default: blank page)'. This adds clear meaning and context beyond the schema's property name and type.

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 states the action clearly: 'Open a new browser tab.' The verb 'open' and resource 'new browser tab' are specific. However, it does not differentiate from sibling tools like zen_duplicate_tab or zen_create_window, which also create new tabs, missing an opportunity to clarify uniqueness.

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 is provided on when to use this tool versus alternatives such as zen_navigate, zen_duplicate_tab, or zen_create_window. The description lacks context for decision-making, leaving the agent to guess the appropriate tool.

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