Selects one or more values in a browser select control using a snapshot reference or unique CSS selector, so automated form interactions can set dropdown options.
Select one or more values in a select control.
| Name | Required | Description | Default |
|---|---|---|---|
| pageId | No | Defaults to the active page | |
| target | Yes | Snapshot ref (e12) or unique CSS selector | |
| values | Yes | ||
| sessionId | No | Defaults to the active session |
Changes observed during successful MCP inspections.
v2026.10.24Input schema / properties / pageId / descriptionPrevious value: -"Stable page ID; defaults to the session active page"New value: +"Defaults to the active page"Input schema / properties / sessionId / descriptionPrevious value: -"Optional session ID; defaults to this MCP client active session"New value: +"Defaults to the active session"Input schema / properties / target / descriptionPrevious value: -"Snapshot ref such as e12, aria-ref=e12, or a unique CSS selector"New value: +"Snapshot ref (e12) or unique CSS selector"v2026.8.14Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full disclosure burden, yet it says nothing about firing change/input events, waiting behavior, multi-select semantics, or failure mode when a value is absent. It only implies a mutation to page state, which is a minimal and obvious inference.
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 front-loaded sentence with no filler or repetition. It is efficient, though slightly too terse for a tool whose behavior needs qualifying.
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?
With no annotations, no output schema, four parameters, and 25% of property descriptions missing, the definition should explain event firing, waiting, and value-matching rules. It does not, leaving the agent under-informed for a state-mutating browser action.
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 75%, and the required `values` array is undocumented in the schema; the description only says 'one or more values', restating minItems:1, and does not clarify whether entries match option labels, option values, or indexes. It adds essentially no 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 names a specific verb ('select') and resource ('select control'), which makes the action clear. It does not differentiate from adjacent siblings such as nex_browser_fill_form, nex_browser_check, or nex_browser_type, leaving the agent to infer that this only applies to <select> elements.
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 tool versus alternatives, nor any exclusions such as 'not for checkboxes — use nex_browser_check'. Usage is only implied by the phrase 'select control'.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.