Revid

List voices

list_voices

Read-only

List the narration voices of the Revid voice picker (gender, accent, age, language, preview URL) to pick voice.voiceId for render_video. The account's cloned voices come first.

Tool call template

This tool declares no required parameters. Add optional parameters from the input schema as needed.

{
  "id": 1,
  "jsonrpc": "2.0",
  "method": "tools/call",
  "params": {
    "arguments": {},
    "name": "list_voices"
  }
}

Input Schema

Name	Required	Description
`age`	No	e.g. young, middle aged.
`limit`	No	Maximum voices returned. Default 100.
`accent`	No	e.g. american, british.
`gender`	No
`search`	No	Words to find in the name or description, e.g. calm, deep.
`category`	No	premade (default): Revid's curated voices. all: the whole public catalog.
`language`	No	Language code, e.g. en, fr.

Output Schema

Name	Required	Description	Default
`ok`	Yes
`data`	No
`error`	No
`method`	Yes
`status`	Yes
`endpoint`	Yes
`retryAfterSeconds`	No

Schema Changelog

Changes observed during successful MCP inspections.

First observedNov 5, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already declare readOnly/non-destructive/closed-world, so the description is not carrying the safety burden. It adds genuine behavioral context beyond those annotations: the attributes returned (gender, accent, age, language, preview URL) and the ordering rule that the account's cloned voices come first, which affects how an agent should pick a default voice. It does not mention pagination or total-count behavior despite a `limit` param.

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, both earning their place: the first establishes scope and the consumption target, the second delivers the ordering caveat. Front-loaded and free of filler.

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?

With an output schema, full annotation coverage, and 86% schema description coverage, the description covers what the structured fields cannot: why the tool exists and how results are ordered. Minor gaps (pagination behavior, default category effects on result set) remain but are low-cost for a read-only list tool.

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 coverage is 86%, so the schema already documents nearly every filter, and the baseline is 3. The description lists gender/accent/age/language as voice attributes but does not disambiguate them as combinable filters, and says nothing about `category`, `search`, or `limit` beyond what the schema states, so it adds little semantic value.

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?

Specific verb + resource ("List the narration voices of the Revid voice picker") plus an explicit downstream purpose: choosing `voice.voiceId` for `render_video`. This makes it unmistakable versus siblings like `clone_voice` or `list_characters`.

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 states clearly when to reach for it — to pick a voiceId to feed `render_video` — which is a real routing signal. It stops short of explicit exclusions (e.g. that it does not create or clone voices; that is `clone_voice`), so it is clear context without full when-not guidance.

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

All Revid tools Inspect

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