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Wait for

wait_for

Poll the screen until a UI element becomes visible or disappears, or timeout. Replaces fixed sleeps with efficient polling to wait only as long as needed.

Instructions

Poll the screen until an element becomes visible or not_visible, or timeout. Replaces fixed sleeps — fast when ready, patient when not.

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": {
      "device_id": "<device_id>"
    },
    "name": "wait_for"
  }
}

Input Schema

Name	Required	Description	Default
`id`	No
`text`	No
`index`	No
`condition`	No		visible
`device_id`	Yes	Device id from list_devices (adb serial like 'emulator-5554', or an iOS simulator UDID)
`timeout_ms`	No
`interval_ms`	No
`resource_id`	No
`accessibility`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedv0.2.0Jul 31, 2026

TDQS

B3.2/5.0

Behavior2/5

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

With no annotations, the description must convey behavior. It discloses polling and timeout, but omits critical details such as what happens on timeout (throws? returns false?), the return value, matching semantics (e.g., first element vs all), and how selectors interact. This is insufficient for a tool with no annotation coverage.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

The description is two sentences, front-loaded with the core action and followed by the benefit. Every word earns its place; it is efficient and easy to scan.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness1/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

This is a complex tool with 9 parameters, no output schema, and no annotations. The description is far too minimal: it does not explain element selectors, timeout behavior, or return values. The tool cannot be used correctly based solely on the description, making it contextually incomplete.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters1/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is only 11% (only device_id has a description), and the description does not explain any of the 8 undocumented parameters (id, text, index, resource_id, accessibility, condition, timeout_ms, interval_ms). The description's mention of 'element' and visibility is vague and does not clarify how to specify targets or configure polling.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

The description uses a specific verb 'poll' and states the resource 'screen' with clear conditions (visible or not_visible) and timeout. It also contrasts with sibling tools like 'assert' and 'find_elements' by focusing on waiting rather than immediate verification.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines4/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

The description explicitly says 'Replaces fixed sleeps', giving a clear use case for when to prefer this tool. However, it does not mention when NOT to use it (e.g., if an immediate assertion is needed) or list alternatives like 'assert'.

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