VideoGen

List text-to-speech voices

list_tts_voices

Read-onlyIdempotent

Return a page of narration voices with voiceId, display name, language, accent, description, deprecation status, and supportsDirectToolExecution. Use a voice with supportsDirectToolExecution true for text_to_speech; nextCursor fetches more voices.

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_tts_voices"
  }
}

Input Schema

Name	Required	Description
`limit`	No	Maximum number of items to return.
`query`	No	Optional case-insensitive substring filter across each item's searchable text fields.
`cursor`	No	Pagination cursor from a previous response's `nextCursor`.
`includeDeprecatedVoices`	No	Whether to include older voices that remain callable. Omit to exclude deprecated voices.

Output Schema

Name	Required	Description
`hasMore`	Yes	Whether another page is available.
`ttsVoices`	Yes	Available text-to-speech voices.
`nextCursor`	Yes	Cursor for the next page, or null.

Schema Changelog

Changes observed during successful MCP inspections.

Changed6 schema fields changedNov 4, 2026
- removedOutput schema / properties / nextCursor / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / nextCursor / type
```
Added value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / ttsVoices / items / properties / accent / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / ttsVoices / items / properties / accent / type
```
Added value: +[
+  "string",
+  "null"
+]
```
- removedOutput schema / properties / ttsVoices / items / properties / description / anyOf
```
Removed value: -[
-  {
-    "type": "string"
-  },
-  {
-    "type": "null"
-  }
-]
```
- addedOutput schema / properties / ttsVoices / items / properties / description / type
```
Added value: +[
+  "string",
+  "null"
+]
```

Changed1 schema field changedOct 16, 2026

changedInput schema / properties / includeDeprecatedVoices / description

Previous value: -"Include deprecated voices in the results."New value: +"Whether to include older voices that remain callable. Omit to exclude deprecated voices."

First observedOct 9, 2026

TDQS

A4.2/5.0

Behavior4/5

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

Annotations already declare read-only, idempotent, non-destructive behavior, so the description's job is reduced. It still adds real value by disclosing pagination via nextCursor and the cross-tool constraint that generated speech requires supportsDirectToolExecution true, which no annotation conveys.

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 compact sentences; the output contract comes first and the actionable cross-tool rule follows. No filler or restatement of the title.

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?

For a four-parameter, fully documented read tool with an output schema, the description covers what matters: return fields, pagination, and the downstream selection criterion. The field list is slightly redundant given the output schema, but nothing an agent needs is missing.

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 100%, so limit, query, cursor, and includeDeprecatedVoices are fully documented in the schema. The description only reinforces the cursor/nextCursor linkage and the deprecation notion, adding little beyond structured data — the baseline 3 applies.

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?

States a specific verb and resource ('Return a page of narration voices') and enumerates the returned fields, so an agent immediately knows the shape of the result. It is clearly distinguishable from sibling generation tools like text_to_speech or generate_avatar.

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?

Gives concrete guidance: use a voice whose supportsDirectToolExecution is true when calling text_to_speech, and use nextCursor to page further. It lacks an explicit alternative or exclusion (e.g. when to use list_languages instead), keeping it below a 5.

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

All VideoGen tools Inspect

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