Pauses browser automation until specified conditions occur, such as element visibility, network idle, text presence, or a JavaScript expression evaluating true.
Unified waiting (supports time/element/disappear/text/URL/loading/network idle/DOM stable/JS conditions)
| Name | Required | Description | Default |
|---|---|---|---|
| ms | No | wait milliseconds | |
| text | No | ||
| type | No | ||
| state | No | ||
| pattern | No | URL match | |
| timeout | No | ||
| selector | No | ||
| expression | No | JS expression |
Changes observed during successful MCP inspections.
v4.3.0Does 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 lists condition types but does not state whether the tool blocks execution, what the default timeout is, what happens on timeout (error vs silent return), or what the return value is. These are critical for a wait operation.
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?
The description is a single sentence with no wasted words, and the core idea 'Unified waiting' is front-loaded. The parenthetical list is efficient, though it could be structured more clearly as a bullet list if longer. Appropriately concise for the amount of information conveyed.
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?
Given 8 parameters, low schema coverage (38%), no annotations, and no output schema, the description is far too sparse. It omits default timeout behavior, blocking semantics, error handling, and how to construct a wait condition. It is not complete enough for an agent to use the tool reliably.
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 description coverage is only 38% (8 parameters, 3 with descriptions). The description loosely maps some condition types but does not explain how to use selector, state, timeout, or how type interacts with other parameters. It adds minimal meaning beyond the schema.
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?
The description states it is a 'unified waiting' tool and lists supported condition types, giving some clarity on what it does. However, it does not distinguish this tool from siblings like wait_for and wait_for_text, leaving ambiguity about when to choose each. The purpose is vague beyond the name itself.
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 is provided on when to use this tool versus alternatives. The parenthetical merely lists supported conditions but offers no context, prerequisites, or exclusions. An agent has no basis for selecting this over wait_for or wait_for_text.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.