selectChoose one or more options in a native HTML dropdown by value, label, or index. For custom dropdowns, click the trigger, then click an option.
Choose one or more options in a native by value, label or index. For custom dropdowns, click the trigger and then click an option with chrome_click.
| Name | Required | Description | Default |
|---|---|---|---|
| ref | No | ||
| index | No | ||
| label | No | ||
| tabId | No | ||
| value | No | ||
| labels | No | ||
| values | No | ||
| frameId | No | ||
| indexes | No | ||
| selector | No |
Changes observed during successful MCP inspections.
v0.1.3Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description carries the full burden. It discloses that one OR more options can be selected (multi-select support), which is useful behavior, but says nothing about what happens on failure, whether selection replaces or appends in a multi-select, or any permission/race considerations.
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 waste, and the positive case plus the excluded case are both front-loaded. Nothing needs trimming.
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 10-param, no-annotation, no-output-schema tool, the description covers intent and the sibling alternative but leaves the element-targeting params (ref/selector) and scoping params (tabId/frameId) undocumented. Adequate for the core call, incomplete for the full parameter surface.
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 0% across 10 parameters, so the description must carry the load. It explains the value/label/index selection families (including plural variants), but leaves ref, selector, tabId, and frameId completely unexplained in both schema and description.
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?
States a specific verb (choose/select) and resource (native <select>), and explicitly distinguishes itself from the custom-dropdown path by naming the chrome_click sibling. An agent can tell this apart from click/hover without opening the schema.
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?
Gives an explicit when-not with an alternative: for native selects use this, for custom dropdowns click the trigger then use chrome_click. It lacks guidance on when to prefer value vs label vs index, but the core routing decision is spelled out.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.