Select an option from a dropdown by CSS selector and value in a browser session to complete forms or apply filters during scraping.
Select an option from a dropdown element.
| Name | Required | Description | Default |
|---|---|---|---|
| value | Yes | Value of the option to select | |
| selector | Yes | CSS selector of the <select> element | |
| session_id | Yes | Session ID returned by browser_navigate |
Changes observed during successful MCP inspections.
v2.7.0Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already disclose readOnlyHint=false, destructiveHint=false, and openWorldHint=true, so the safety profile is covered structurally. The description adds nothing beyond that: it does not say whether change events fire, how an invalid value or missing option is handled, or whether the selection is verified. For a mutation tool this is a notable gap.
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 with no filler and the key information (select, option, <select> dropdown) front-loaded. It is efficient, though its brevity edges toward under-specification rather than pure conciseness.
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 a simple three-parameter tool with full schema coverage, annotations, and no output schema, the description covers the core action adequately. It omits failure behavior (option not found, hidden/disabled options) and event side effects, which an agent calling a stateful browser mutation would benefit from knowing.
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 100%, with value, selector, and session_id all documented, so the schema carries the parameter burden and the baseline is 3. The description adds only a marginal clarification that the selector targets a <select> element rather than any arbitrary node.
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?
Names a specific verb ('select') and a specific resource ('option from a <select> dropdown element'), which is unambiguous on its own. It stops short of differentiating from near-siblings like browser_click or browser_fill, which could also target a select element, so it is clear but not sibling-aware.
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?
There is no statement of when to use this instead of browser_click, browser_type, or browser_fill, nor any prerequisite such as the select needing to be present or the session needing a prior browser_navigate. Usage context is left entirely to inference from the name.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.