Selects an option in a dropdown by its value, using a ref or selector, and reports the resulting network, console, and URL changes.
Select an option (by value) in a element (by ref from page_snapshot, or CSS selector) and report the network/console/url delta it caused.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | No | ||
| value | Yes | ||
| waitMs | No | settle time after selecting before reporting the delta (default 700ms) | |
| selector | No | ||
| sessionId | No |
Changes observed during successful MCP inspections.
v0.6.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
With no annotations provided, the description carries the burden of behavioral disclosure. It does reveal that selecting triggers a delta report and implies a settle time via waitMs, but it does not state whether the action is destructive, reversible, or may cause navigation, which is a notable gap for an interaction tool.
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 sentence that is front-loaded with the action and resource, and includes both the selection method and the reporting outcome. No filler or redundancy.
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 an interaction tool with no output schema, the description adequately conveys the return (network/console/url delta) and the settle behavior via waitMs. It omits details about sessionId and error cases, but given the tool's straightforward purpose, it is reasonably complete.
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 only 20% (waitMs only), so the description compensates by explaining ref and selector as alternative locators and clarifying that value is the option to select. However, sessionId is not explained, and the description does not detail the format of the delta report, leaving some parameters under-documented.
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 clearly states the action (select an option by value), the target resource (a <select> element), and how to locate it (by ref or CSS selector). It also notes the side effect of reporting the network/console/url delta, distinguishing it from sibling tools like page_click or page_fill.
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?
The description implies usage for select elements but does not explicitly contrast it with alternatives or state when not to use it. It mentions the mechanism for locating elements (ref or selector) but offers no exclusions or prerequisites, leaving some inference required.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.