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Playwright MCP Server

Playwright MCP Server

Official
by microsoft
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TypeScript
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browser_tabs

Destructive

List, create, close, or select browser tabs to manage active pages and navigate to URLs.

Instructions

List, create, close, or select a browser tab.

Input Schema

NameRequiredDescriptionDefault
urlNoURL to navigate to in the new tab, used for new.
indexNoTab index, used for close/select. If omitted for close, current tab is closed.
actionYesOperation to perform
isolatedContextNoName of an isolated browser context to create the new tab in, used for new. Tabs in the same isolated context share cookies and storage, tabs in different contexts are fully isolated. If omitted or "default", the tab is created in the default context.

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed1 schema field changedv0.0.84
    • addedInput schema / properties / isolatedContext
      Added value: +{
+  "description": "Name of an isolated browser context to create the new tab in, used for new. Tabs in the same isolated context share cookies and storage, tabs in different contexts are fully isolated. If omitted or \"default\", the tab is created in the default context.",
+  "type": "string"
+}
  2. Changed2 schema fields changedv0.0.72
    • changedInput schema / $schema
      Previous value: -"http://json-schema.org/draft-07/schema#"New value: +"https://json-schema.org/draft/2020-12/schema"
    • addedInput schema / properties / url
      Added value: +{
+  "description": "URL to navigate to in the new tab, used for new.",
+  "type": "string"
+}
  3. Addedv1.0.1

TDQS

C2.9/5.0
Behavior2/5

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

Annotations already declare readOnlyHint=false, destructiveHint=true and openWorldHint=true, so the safety profile is covered structurally. The description adds nothing beyond that: it does not warn that closing destroys tab state, does not say whether closed tabs are recoverable, and does not describe what 'list' returns or how tab indices are ordered.

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 with no wasted words, and the operation list is ordered to match the enum. It is efficient, though the terseness contributes to the gaps noted in other dimensions.

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?

For a multi-action tool with four parameters and no output schema, the description should at minimum explain what 'list' returns and how indices behave. Nothing about return values, index stability across tab changes, or the effect of isolatedContext on subsequent operations is conveyed, leaving the agent to reconstruct behavior from the schema alone.

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

Parameters3/5

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

Schema description coverage is 100%, including the url, index, and isolatedContext descriptions, so the schema does the heavy lifting for parameter meaning. The description only restates the operation names and adds no syntax or format detail beyond what the schema already provides.

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?

The description names a specific resource (browser tab) and enumerates the four operations (list, create, close, select) that map directly to the action enum. It is clear what the tool does, but it offers no differentiation from the sibling browser_close, which an agent could easily confuse with the 'close' action here.

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?

There is no guidance on when to use this tool versus alternatives such as browser_close or browser_navigate, and no prerequisites or exclusions are stated. Usage is only implied by the action enum, which the agent must infer from the schema.

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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