real-browser-mcp

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browser_drag

Drag elements or coordinates from one point to another using CDP mouse events for reliable drag-and-drop; specify start and end refs, selectors, or x/y positions.

Instructions

Drag from one element or position to another. Uses CDP mouse events for reliable drag-and-drop. Provide either refs/selectors or explicit x,y coordinates.

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_drag"
  }
}

Input Schema

Name	Required	Description
`endX`	No	End X coordinate (if not using ref/selector)
`endY`	No	End Y coordinate (if not using ref/selector)
`steps`	No	Number of intermediate mouse move steps
`endRef`	No	Ref of the element to drag to
`startX`	No	Start X coordinate (if not using ref/selector)
`startY`	No	Start Y coordinate (if not using ref/selector)
`startRef`	No	Ref of the element to drag from
`endSelector`	No	CSS selector of the element to drag to
`startSelector`	No	CSS selector of the element to drag from

Schema Changelog

Changes observed during successful MCP inspections.

Addedv1.3.0Oct 19, 2026

TDQS

B3.4/5.0

Behavior3/5

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

With no annotations, the description carries the full behavioral burden. It usefully discloses the implementation ('Uses CDP mouse events for reliable drag-and-drop'), implying real synthesized mouse input, but omits return behavior, failure modes, and any permission or timing caveats.

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?

Three short sentences, front-loaded with the core action and followed by the implementation note and input-mode hint. No filler, and each sentence adds a distinct piece of information.

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?

For a 9-parameter, no-annotation tool the description is only minimally sufficient: it covers the two addressing modes and the mechanism, but says nothing about return values (no output schema exists) or edge behavior like element not found. Adequate but leaves clear gaps.

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%, so the baseline is 3. The description adds a coarse grouping (refs/selectors vs x,y coordinates) that helps an agent pick between the two addressing modes, but adds no detail on 'steps' or other parameters 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?

The description names a specific verb (drag) and resource (element/position) and clarifies it moves from one point to another, which is clearly distinct from siblings like browser_click and browser_hover. It stops short of naming an alternative tool, but the operation is unambiguous on its own.

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 parameter-mode guidance ('Provide either refs/selectors or explicit x,y coordinates'), which helps an agent choose an input strategy. However, it offers no when-to-use vs when-not guidance relative to other interaction tools such as click or hover.

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