Closes the currently open page in a headless browser session, terminating the active context and releasing resources.
Close the page
This tool declares no required parameters. Add optional parameters from the input schema as needed.
{
"id": 1,
"jsonrpc": "2.0",
"method": "tools/call",
"params": {
"arguments": {},
"name": "browser_close"
}
}| Name | Required | Description | Default |
|---|---|---|---|
No arguments | |||
Changes observed during successful MCP inspections.
v0.0.77Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
The annotation already indicates destructiveHint=true, so the agent knows the action is destructive. The description simply repeats that by saying 'close' without adding any extra context about side effects (e.g., whether it closes just the current tab, loses unsaved state, or affects other tabs). It does not contradict the annotation, but it adds no new behavioral information.
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 extremely concise, using only three words. It communicates the essential action and target without any fluff, making it easy to parse and understand quickly.
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 the simplicity of the tool (no parameters, no output schema), the description is functional but lacks completeness. It leaves open the scope of 'close'—does it close the current page/tab, or the entire browser? In a context with sibling tools like browser_tabs, this ambiguity could be problematic. More detail would improve it.
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?
There are no parameters, so the schema coverage is trivially complete at 100%. The description does not need to explain any parameter semantics, and the baseline score 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 the page' clearly states the action (close) and the resource (page), making it unambiguous. It is distinct from sibling tools like browser_navigate or browser_snapshot, so an agent can easily identify it.
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 potential alternatives (e.g., using browser_tabs to manage multiple pages) or any conditions that would make closing appropriate. The context is minimal and leaves the decision entirely to the agent.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.