Move a webpage element by dragging its source CSS selector onto a target selector within a browser session.
Drag an element from its current position to a target element.
| Name | Required | Description | Default |
|---|---|---|---|
| session_id | Yes | Session ID returned by browser_navigate | |
| source_selector | Yes | CSS selector of the element to drag | |
| target_selector | Yes | CSS selector of the drop target |
Changes observed during successful MCP inspections.
v2.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already declare readOnlyHint=false, destructiveHint=false and openWorldHint=true, so the safety profile is covered. The description adds nothing beyond them: no mention of whether HTML5 drag events fire, whether intermediate mouse moves occur, or what happens when the source or target selector is not found.
Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.
Is the description appropriately sized, front-loaded, and free of redundancy?
A single front-loaded sentence with zero padding that states the action and its two endpoints. It is appropriately short, though it is arguably too thin to be maximally useful rather than verbose.
Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.
Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?
For a three-parameter interaction tool with full schema coverage and annotations covering safety, the description is minimally viable. It omits failure behavior, visibility/viewport requirements, and drag-event semantics, which an agent would want before invoking it in a browser session.
Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.
Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?
Schema coverage is 100% and each of the three parameters is documented in the schema (session_id, source CSS selector, target CSS selector). The description merely restates the source/target relationship without adding format or syntax detail, so the baseline 3 applies.
Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.
Does the description clearly state what the tool does and how it differs from similar tools?
States a specific verb ('Drag') and resource ('an element') with source and target positions, which clearly separates it from siblings like browser_click and browser_hover. It does not explicitly name those alternatives, but the action itself is unambiguous.
Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.
Does the description explain when to use this tool, when not to, or what alternatives exist?
No guidance on when to use this versus browser_click, browser_hover, or browser_evaluate-driven drag scripts, and no prerequisites such as elements needing to be visible or in the viewport. The agent must infer the use case entirely.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.