close

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. The description only states what it does (closes the tab) but does not mention whether this is destructive, whether it requires confirmation, or whether the tab's state is lost. Since closing a tab is a mutation with potential data loss, this is a significant omission.

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 that conveys the complete action. There is no unnecessary information or repetition, and the verb is front-loaded. Perfectly concise.

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 no parameters and a simple action, the description is largely complete. It identifies the target (current tab) and the action (close). However, given the lack of annotations, it could note the destructive nature of closing a tab, but the tool's simplicity and lack of parameters make it adequate. Overall, an agent can call it correctly without ambiguity.

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, which sets a baseline of 4 per the rubric. Since there are no parameters to explain, the description does not need to add parameter details. It correctly omits any parameter discussion.

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 states the verb 'close' and the resource 'current tab', making the action unambiguous. It is distinct from sibling tools (click, browse, back) as none of them perform closing. A specific action with no ambiguity.

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?

There is no explicit guidance on when to use this tool versus alternatives. However, the action is self-explanatory and the context of 'current tab' implies it is used for closing a browsing tab. No exclusions or alternatives are mentioned, so the usage context is implied rather than explicit.

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