jevpilot

browser_tabs

List, select, or close tabs in a browser session to control which page automation uses and prevent work from running in the wrong tab.

Instructions

List, select, or close tabs owned by a browser session.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "session": "<session>",
      "action": "<action>"
    },
    "name": "browser_tabs"
  }
}

Input Schema

Name	Required	Description
`action`	Yes
`tab_id`	No
`session`	Yes	Session ID returned by browser_run.

Output Schema

Name	Required	Description	Default
`tabs`	No
`closed`	No
`reason`	No
`status`	No
`session`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Sep 29, 2026

TDQS

C2.7/5.0

Behavior2/5

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

With no annotations, the description carries the full behavioral burden, yet it does not disclose that 'close' is destructive/irreversible, what 'select' changes (active/focused tab state), or any permission requirements. The only added context is the ownership scoping phrase 'owned by a browser session.'

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

Conciseness4/5

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

A single front-loaded sentence that wastes no words and enumerates the modes efficiently. It is arguably too terse, but there is no filler or redundancy.

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

Completeness2/5

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

An output schema exists so return values need not be explained, but with no annotations and only one of three parameters documented, the action-to-parameter contract (especially tab_id) is left incomplete for a tool that can also destroy state via close.

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

Parameters2/5

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

Schema coverage is only 33% (just the session param). The description does not clarify that tab_id is required for select/close (it is not in the required list), how to obtain a tab_id, or how the action enum interacts with tab_id. It adds no meaning beyond the schema.

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

Purpose4/5

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

States three specific verbs (list, select, close) against a clear resource (tabs owned by a browser session). It does not explicitly contrast with siblings like browser_close or browser_run, but the resource scope is unambiguous enough for selection.

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

Usage Guidelines2/5

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

No when-to-use guidance beyond restating the three enum actions. It does not say when to pick this over browser_close for tearing down a session, nor which action to choose in a given situation, so the agent must infer everything.

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

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