browser-mcp

browser_ensure_real_tab

Switches to a real browser tab when the current one is a chrome:// page or stale, ensuring subsequent browser actions target a valid page.

Instructions

Switch to a real (non-internal) tab if the current one is chrome:// or stale.

Tool call template

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_ensure_real_tab"
  }
}

Input Schema

Name	Required	Description	Default
No arguments

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 18, 2026

TDQS

A4.2/5.0

Behavior3/5

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

With no annotations, the description carries the burden of behavioral disclosure. It clearly discloses the conditional tab switch, but leaves 'stale' undefined and does not explain what happens if no real tab exists or how the replacement tab is chosen. Core behavior is stated, but side-effect details are thin.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

One sentence carries the action, target, and trigger condition with no filler. It is front-loaded and every word earns its place.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a zero-parameter, no-output-schema utility, the description supplies the key context: when to run it and what it accomplishes. Slight ambiguity in 'stale' is the only notable gap.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters4/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

The tool takes zero parameters, so there is no parameter semantics for the description to add. The 100% schema coverage makes this trivially complete, and the baseline of 4 applies.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb ('Switch') with a clear resource ('real (non-internal) tab') and an explicit condition ('if the current one is chrome:// or stale'). This distinguishes it from browser_switch_tab and other navigation tools. The purpose is immediately obvious.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

It states exactly when to invoke the tool: when the current tab is an internal chrome:// page or is stale. It does not name alternatives or state when not to use it, so it falls short of a full 5, but the trigger condition is clear.

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