browser_tabs

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

With no annotations provided, the description carries the full burden of behavioral disclosure. It only lists the operations without explaining side effects such as whether creating a tab navigates immediately, whether closing the current tab without an index behaves differently, or what 'select' does in terms of focus. It also does not mention any return values, permissions, or impact on the session. The description is a bare enumeration, not a transparent explanation of behavior.

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 that front-loads the core purpose and lists all actions concisely. There is no redundancy, fluff, or unnecessary detail. Every word earns its place, making it highly efficient for an agent to parse.

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?

The tool has 4 parameters and multiple actions, but no output schema and no annotations. The description does not explain what 'list' returns, how indices are interpreted (beyond schema notes), or what happens when closing without an index. While the schema covers parameter syntax, the description lacks behavioral and output context, making it incomplete for an agent to fully understand the tool's effects and return values. A more complete description would mention return format and action-specific behaviors.

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 100%, so each parameter (url, index, action, sessionId) is already documented in the input schema. The tool description adds no parameter-level information. Per the baseline rule, when schema coverage is high, a score of 3 is appropriate—the schema does the heavy lifting, and the description provides no additional value for parameter understanding.

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 specifies the tool's scope with the verb 'List, create, close, or select' and explicitly names the resource ('browser tab'). It also enumerates the distinct actions, which distinguishes it from sibling tools like browser_navigate or browser_click that focus on page-level operations. This is a specific and unambiguous purpose statement.

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 usage by listing the available actions (list, create, close, select), suggesting when to use the tool for tab management. However, it does not explicitly state when to prefer this tool over alternatives (e.g., when to use browser_navigate for navigation vs. browser_tabs for tab selection) or provide any contextual rules or exclusions. Usage is only implied through the action list, not explicitly guided.

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