browser_switch_tab

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

No annotations are provided, so the description carries the full burden. It clearly states the core state-changing behavior—switching the active tab—but does not mention how invalid indexes are handled or whether the switch triggers any navigation or waiting behavior. This is acceptable for such a simple operation, but not richly transparent.

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 short sentence with no filler. Every word contributes meaning, and the important 'from browser_tabs' qualifier is included inline without bloating the text.

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?

This is a low-complexity tool with one required parameter and no output schema. The description tells the agent what action to perform and where to obtain the index. It could additionally mention index bounds or the result of an invalid index, but the definition is nearly complete for safe invocation.

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 input schema only defines 'index' as a number with no description. The text adds meaning by specifying that the index comes from browser_tabs, which tells the agent where to source the value and that it represents a tab's position in that list. It does not state whether the index is zero-based or bounded, but the source hint is valuable.

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') with a clear resource ('a tab') and the exact selection mechanism ('by index (from browser_tabs)'). This clearly distinguishes it from sibling tools like browser_open and browser_new_tab, which create or load tabs rather than activate an existing one.

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 parenthetical '(from browser_tabs)' implies the correct workflow: list existing tabs, then switch by using one of their indexes. However, it does not explicitly state when not to use this tool, such as 'use browser_new_tab to open a new tab instead'.

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