Select an option in a native select element by visible text or value. For custom dropdowns, click the trigger then click the option.
Select an option in a native element by visible text or value. For custom dropdowns, click the trigger then click the option.
| Name | Required | Description | Default |
|---|---|---|---|
| tabId | No | ||
| option | Yes | Visible option text or value (exact or substring) | |
| target | Yes |
Changes observed during successful MCP inspections.
v0.2.1Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden for a DOM-mutating action. It discloses that matching may be exact or substring via the schema, but says nothing about whether change/blur events fire, whether the element must be visible or in view, or what happens when no option matches.
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?
Two sentences, zero padding, with the primary native-select case front-loaded and the fallback strategy immediately after. Every sentence earns its place.
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 3-parameter, no-annotation, no-output-schema browser action, the description covers the core behavior and its main alternative. Missing are the target-parameter format, failure behavior when the option is absent, and any waiting/visibility expectation, which an agent would need for reliable invocation.
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 33%: only 'option' is documented (exact or substring match), while 'target' and 'tabId' have no schema descriptions. The description echoes the text-or-value semantics of 'option' but adds nothing about how 'target' is specified or why 'tabId' matters, so it only partially compensates for the low coverage.
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 a specific verb (Select) and resource (an option in a native <select> element) and even names the input mode ('by visible text or value'). It implicitly distinguishes itself from the sibling click tool by scoping itself to <select> elements, though it doesn't name click directly.
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?
It gives a clear conditional rule: use this tool for native <select> elements, but for custom dropdowns fall back to click-the-trigger-then-click-the-option. That routes the agent between this tool and siblings. It stops short of explicit when-not cases (e.g. disabled selects, hidden elements).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.