@nxavis/agent-browser-mcp

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browser_is_visible

Check whether an element is visible on a web page using its selector and browser session ID. Returns a boolean to confirm UI state for automation.

Instructions

Check if an element is visible

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": {
      "selector": "<selector>"
    },
    "name": "browser_is_visible"
  }
}

Input Schema

Name	Required	Description	Default
`selector`	Yes	Selector for the element
`sessionId`	No	Browser session ID

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.1Aug 2, 2026

TDQS

C2.9/5.0

Behavior2/5

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

With no annotations, the description carries the full burden of behavioral disclosure. It only says 'check if visible' and does not clarify return format (e.g., boolean), whether it waits for visibility or checks immediately, error handling for missing elements, or whether it triggers any side effects.

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?

The description is a single, direct sentence that efficiently conveys the core purpose. There is no wasted text, though it could be more informative without losing conciseness.

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?

The tool is simple but still lacks essential context: no output schema, no annotations, and no description of return values or behavior on missing elements. For a check-type tool, the user likely needs to know if it returns a boolean or throws an exception, which is omitted.

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%, with 'Selector for the element' and 'Browser session ID' being accurate though generic. The description itself adds no additional parameter context, so the schema provides the baseline which is sufficient.

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 states a specific action (check) and resource (element visibility), which is clear. However, it does not explicitly distinguish from sibling state-check tools like browser_is_enabled or browser_is_checked, though the name itself makes the purpose unambiguous.

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 is provided on when to use this tool versus alternatives such as browser_wait_for_selector or browser_snapshot. There is no mention of prerequisites, such as the element needing to exist or be attached to the DOM, nor when not to use it.

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