BrowserMCP Extended

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browser_drag_drop

Drag one page element onto another by specifying CSS selectors for the source and target to automate drag-and-drop actions in Chrome or Chromium.

Instructions

Perform a drag-and-drop operation between two elements identified by CSS selectors

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": {
      "sourceSelector": "<sourceSelector>",
      "targetSelector": "<targetSelector>"
    },
    "name": "browser_drag_drop"
  }
}

Input Schema

Name	Required	Description	Default
`sourceSelector`	Yes	CSS selector of the drag source
`targetSelector`	Yes	CSS selector of the drop target

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.0.0Nov 2, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are provided, so the description carries the full burden and does not meet it. Drag-and-drop is behaviorally treacherous — it may dispatch HTML5 dragstart/dragover/drop events or synthetic mouse movements, may or may not auto-scroll or hover between steps, and may fail silently on framework-based drag libraries — none of which is disclosed, nor is what happens on failure.

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 filler; nothing is wasted, though nothing is added either. Appropriately sized for a two-parameter tool, just under-informative rather than bloated.

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?

With no annotations and no output schema, the description is the only source of behavioral information for a mutating UI interaction, and it says nothing about success/failure signalling, timing, or event model. For a drag-and-drop operation, where the mechanism matters far more than the two obvious selectors, this is a substantial gap.

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%: both sourceSelector and targetSelector are documented in the schema as CSS selectors for the drag source and drop target. The description restates that at the same level of detail without adding selector-resolution semantics (e.g. first match, shadow DOM, visibility requirements), so the baseline 3 applies.

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?

Names a specific verb (drag-and-drop) and the two resources involved (source and target elements by CSS selector), so the operation is unambiguous. However, a sibling tool literally named browser_drag exists, and the description gives no clue how the two differ, leaving the agent unable to discriminate without opening both schemas.

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 guidance on when this is preferred over browser_drag, browser_click, or browser_hover, and no prerequisites such as elements needing to be visible, in the viewport, or in the same frame. The agent must infer the selection criteria entirely from the tool names.

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