easy-ui-mcp

Overview Schema Source Related Servers Discussions Admin

ui_navigate

ui_navigate

Navigate an open browser session to a specified URL and return the navigation result, enabling AI agents to drive Playwright-based UI testing.

Instructions

Navigate the browser to the given URL and report the result.

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": {
      "url": "<url>"
    },
    "name": "ui_navigate"
  }
}

Input Schema

Name	Required	Description	Default
`url`	Yes	The URL to navigate to
`session_id`	No	Which open session to act on, as returned by ui_start_session. Optional with one open session; required when several are open.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.1.0Nov 10, 2026

TDQS

C2.9/5.0

Behavior2/5

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

No annotations are supplied, so the description carries the full burden, and "report the result" is the only behavioral claim. It does not say whether navigation blocks until load, how redirects or HTTP errors are surfaced, what timeouts apply, or what a failed navigation leaves the session in.

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. The trailing "and report the result" is low-value but not harmful padding.

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?

A two-parameter tool with a fully documented schema and no output schema, so the minimum is met. Still, for a browser navigation primitive the absence of any statement about load waiting, error surfacing, or session prerequisites leaves a real gap for an agent orchestrating a session.

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 coverage is 100%, so both url and session_id are fully documented in the schema, including the single-vs-multiple session rule. The description adds no meaning beyond that, which is the baseline case for complete schemas.

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?

States a specific verb and resource ("Navigate the browser to the given URL") and adds an outcome clause. An agent can tell this is the page-loading tool apart from click/fill/assert siblings, though the near-identical sibling ui_navigate_history is not addressed, so the boundary there must be inferred.

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 when-to-use guidance at all: nothing says this must follow ui_start_session, nothing distinguishes it from ui_navigate_history or ui_tabs, and no preconditions (session open, page ready) are stated. The only routing information lives in the schema, not the description.

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