Chrome Browser Control

Overview Schema Source Related Servers Discussions Admin

List frame documents

list_frames

List current frame documents for a specified Chrome tab, identifying blocked or unsupported frames that cannot be targeted.

Instructions

List current frame documents for an allowed target tab. Blocked or unsupported frames are redacted and cannot be targeted.

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": "list_frames"
  }
}

Input Schema

Name	Required	Description	Default
`tabId`	No	Optional Chrome tab id. Defaults to the claimed session tab, then the active tab.
`sessionTabId`	No	Optional claimed tab session id returned by claim_tab.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.4.0Sep 10, 2026

TDQS

A3.7/5.0

Behavior3/5

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

With no annotations, the description carries the full transparency burden. It does disclose a useful behavioral trait: blocked or unsupported frames are redacted and cannot be targeted, and 'current' implies a snapshot-style read. However, it leaves 'allowed target tab' undefined and does not explain failure modes, authorization prerequisites, or what side effects (if any) occur, which are notable gaps for a no-annotation tool.

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?

The description is extremely efficient: two sentences, the action comes first, and the second sentence adds the only redaction detail an agent needs. There is no redundant padding; every clause contributes a distinct aspect of the tool's behavior.

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

Completeness3/5

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

The tool has only two optional parameters and full schema coverage, so it does not need exhaustive explanation of inputs, but it leaves important operational details unaddressed: it does not describe the expected return shape of 'frame documents', the meaning of 'allowed target tab', or error behavior when no tabs are allowed. These gaps are moderate for a seemingly simple listing tool.

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 the 100% and each parameter's meaning and default behavior is already documented in the schema. The description adds no further parameter-level detail beyond the notion of an 'allowed target tab', which stays aligned with the schema but does not enhance it.

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 states a specific verb ('List') on a concrete resource ('current frame documents') and scopes it to 'an allowed target tab', which clearly distinguishes it from tab-level tools like list_tabs. The added note that blocked/unsupported frames are redacted further clarifies what the tool exposes.

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

Usage Guidelines3/5

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

The description gives context about targeting tabs through the phrases 'allowed target tab' and 'redacted... cannot be targeted', but it never explicitly says when to prefer this tool over alternatives like list_tabs or snapshots. Usage is implied rather than direct, with no exclusion criteria or sibling comparisons.

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