veilbrowser

veil_select

Set a select dropdown to a value using a snapshot ref, firing input and change events to reliably drive native selects.

Instructions

Set a dropdown (by snapshot ref) to a value and fire input+change — the reliable way to drive a native , which click+type can't. Value matches an option's value, then its visible label/text.

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": {
      "ref": "<ref>",
      "value": "<value>"
    },
    "name": "veil_select"
  }
}

Input Schema

Name	Required	Description	Default
`ref`	Yes
`value`	Yes

Schema Changelog

Changes observed during successful MCP inspections.

First observedv1.5.0Jul 29, 2026

TDQS

A4.5/5.0

Behavior4/5

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

With no annotations, the description discloses key behaviors: it fires input+change events and matches the value against the option's value attribute, then its visible text. It does not cover failure cases or return values, but adds meaningful behavioral insight beyond the schema.

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?

Two sentences, front-loaded with the action, no redundant words. Every sentence adds value.

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?

Given the tool's simplicity (2 params, no output schema), the description covers purpose, parameters, and key behavior. It could mention prerequisites (e.g., existing snapshot) or error handling, but overall is fairly complete.

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

Parameters5/5

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

Schema has 0% description coverage, so the description fully explains both parameters: 'ref' is a snapshot reference, 'value' is the value to set, with matching logic detailed (matches option value, then label). This adds significant meaning beyond the type-only schema.

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?

The description clearly states the tool sets a native <select> dropdown to a value and fires input+change events. It distinguishes itself from click+type, which cannot reliably drive a native <select>.

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

Usage Guidelines4/5

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

The description explicitly positions this tool as the reliable way to handle native <select> elements, contrasting it with click+type. It does not discuss alternative sibling tools or when not to use it, but provides clear context for its use.

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