switch_to_newest_tab

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

No annotations are provided, so the description carries the behavioral disclosure burden. It clearly states the active-tab change, but it does not describe what happens when no other tab exists, whether the current tab is closed, or whether the operation returns any tab information. The core action is unambiguous, but edge-case behavior is undisclosed.

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, front-loaded sentence with no filler or redundant phrasing. It earns its place by immediately stating the action and target.

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 zero-parameter, single-action tool, the description is mostly complete. The action is fully described, and no return-value details are needed since an output schema exists. The only gaps are comparative context with switch_to_tab and behavior when no newest tab exists.

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 tool has zero parameters and the schema already fully represents this with an empty properties object. There is no parameter meaning for the description to add, so the baseline 4 applies.

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 uses a specific verb, 'Switch,' and a clear target, 'the most recently opened tab.' This distinguishes it from sibling tools like switch_to_tab, which implies switching to a user-specified tab, and open_new_tab, which creates 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 wording implies the intended use case: the agent should call this when it needs to focus on the newest tab. However, it does not explicitly state when to prefer this over switch_to_tab, nor does it mention any exclusions or prerequisites, such as whether a tab must already exist.

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