Close the active tab in a Chrome MCP session, optionally targeting a specific session, to end that tab's page context and free it for other work.
Close the current tab in the session.
| Name | Required | Description | Default |
|---|---|---|---|
| session | No | Per-call session override (does not change the process default) |
Changes observed during successful MCP inspections.
v1.3.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry the full burden of behavioral disclosure. While 'Close the current tab' indicates a destructive action, it does not mention irreversibility, potential loss of unsaved work, behavior when closing the last tab, or which tab becomes active afterward. This is insufficient for a mutation operation.
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, focused sentence with no unnecessary words. It is front-loaded with the core action and easily parsed by an agent.
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?
Given this is a destructive action with no annotations and no output schema, the description should explain consequences and side effects to be contextually complete. It only states the action, omitting important details like tab closure behavior, session implications, or error conditions. This is a clear gap for a tool that removes a resource.
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 schema fully documents the single 'session' parameter with a clear description ('Per-call session override (does not change the process default)'), so schema coverage is 100%. The description adds no extra meaning beyond this, but none is needed because the schema already covers the parameter adequately.
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 specific action ('Close the current tab') and the resource ('in the session'), which precisely differentiates it from sibling tools like wb_close_session (closes session) and wb_go_back (navigation). This is a specific verb+resource pairing that leaves 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?
The description offers no guidance on when to use this tool versus alternatives. It simply states the action without providing context, prerequisites, or exclusions. An agent is left to infer usage from the name alone, with no explicit comparison to siblings like wb_close_session or wb_list_tabs.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.