chrome_close_tab

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 implies a destructive action (closing a tab) but does not state that the action is irreversible, may lose unsaved data, or what happens with an invalid index. This is a significant transparency gap for a mutation tool.

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, concise sentence with no wasted words. It directly states the action and the key parameter.

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 simple one-parameter tool, the description is adequate but minimal. It does not mention error behavior (e.g., out-of-bounds index), side effects on the current tab, or whether the operation is undoable. Given no output schema and no annotations, a slightly richer description would be expected, but the tool is simple enough that this is borderline acceptable.

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 already documents the 'index' parameter with a description ('Tab index to close (0-based)') at 100% coverage. The description adds no additional meaning beyond repeating that the tab is closed by index, so the baseline of 3 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 'Close a tab by index' uses a specific verb (Close) and resource (tab), and clearly distinguishes from sibling tools like chrome_select_tab or chrome_list_tabs. The action is unambiguous and unique among the provided siblings.

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 provides no guidance on when to use this tool versus alternatives. It does not mention prerequisites, such as ensuring the tab index is valid, or contrast with other tab-related operations.

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