gecko-mcp

by Frumane

Overview Schema Source Related Servers Discussions Admin

TypeScript

Local

select_option

Select an option in a dropdown by its value or visible text. Targets the active tab or a specified browser tab.

Instructions

Choose an option in a dropdown by its value. Active tab unless browserId given.

Tool call template

Replace each placeholder with a value matching the input schema. Only required parameters are included; add optional parameters as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {
      "selector": "<selector>",
      "value": "<value>"
    },
    "name": "select_option"
  }
}

Input Schema

Name	Required	Description
`selector`	Yes	CSS selector of the <select>.
`value`	Yes	The option value (or visible text) to select.
`browserId`	No	Target tab. Defaults to active.

Schema Changelog

Changes observed during successful MCP inspections.

First observedv2.2.4Jun 20, 2026

TDQS

A3.6/5.0

Behavior2/5

Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already indicate safe write (readOnlyHint=false, destructiveHint=false). Description adds no additional behavioral traits such as side effects, requirements, or what happens if element is missing. Fails to provide beyond annotation context.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness5/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Single sentence plus one clarifying phrase. No redundant words, front-loaded with action and resource.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness4/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

Adequate for a simple tool with only 3 parameters and no output schema; covers the core behavior and default target. Could briefly mention waiting behavior but not essential.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Parameters3/5

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema covers all 3 parameters with descriptions. Description adds minor clarification about 'value' and 'browserId' default. Baseline 3 maintained as schema does most of the work.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Purpose5/5

Does the description clearly state what the tool does and how it differs from similar tools?

Description clearly states the action ('Choose'), the resource ('option in a <select> dropdown'), and the method ('by its value'). It distinguishes itself from sibling tools like 'click' or 'type_text' by targeting a specific UI element type.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Usage Guidelines3/5

Does the description explain when to use this tool, when not to, or what alternatives exist?

Provides context about defaulting to active tab unless browserId given, but does not explicitly state when to use this tool versus alternatives like 'click' or 'type_text'. Implied usage but no exclusions.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.