Send a voice message (PTT) on WhatsApp by providing base64 audio data or a voice file URL.
Send a voice message (PTT). Provide either data (base64) or url.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | Recipient JID | |
| data | No | Base64 encoded voice data | |
| url | No | URL of the voice file | |
| mimeType | No | MIME type (auto-detected if omitted) | |
| mentions | No | ||
| replyTo | No | ||
| replyToSenderId | No | ||
| isForwarded | No | ||
| viewOnce | No | ||
| ephemeralExpiration | No |
Changes observed during successful MCP inspections. Dates show when Glama detected each change.
v2.0.0Input schema / properties / dataAdded value: +{
+ "description": "Base64 encoded voice data",
+ "type": "string"
+}Input schema / properties / ephemeralExpirationAdded value: +{
+ "enum": [
+ "off",
+ "24h",
+ "7d",
+ "90d"
+ ],
+ "type": "string"
+}Input schema / properties / isForwarded / descriptionRemoved value: -"Whether the message should be marked as forwarded"Input schema / properties / isForwarded / optionalRemoved value: -trueInput schema / properties / mentions / descriptionRemoved value: -"List of phone numbers to mention"Input schema / properties / mentions / optionalRemoved value: -trueInput schema / properties / mimeTypeAdded value: +{
+ "description": "MIME type (auto-detected if omitted)",
+ "type": "string"
+}Input schema / properties / replyTo / descriptionRemoved value: -"ID of the message being replied to"Input schema / properties / replyTo / optionalRemoved value: -trueInput schema / properties / replyToSenderIdAdded value: +{
+ "type": "string"
+}Input schema / properties / to / descriptionPrevious value: -"Recipient phone number (with @s.whatsapp.net) or group ID (with @g.us)"New value: +"Recipient JID"Input schema / properties / urlAdded value: +{
+ "description": "URL of the voice file",
+ "type": "string"
+}Input schema / properties / viewOnce / descriptionRemoved value: -"Whether the voice message should be sent as view-once"Input schema / properties / viewOnce / optionalRemoved value: -trueInput schema / properties / voiceBase64Removed value: -{
- "description": "Base64 encoded voice data (alternative to voiceURL)",
- "optional": true,
- "type": "string"
-}Input schema / properties / voiceURLRemoved value: -{
- "description": "URL of the voice file to send (alternative to voiceBase64)",
- "optional": true,
- "type": "string"
-}Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
No annotations are provided, so the description must carry full burden. It discloses that the tool sends a voice message but omits behavioral traits such as required permissions, file size limits, validation of inputs, or effects on chat. Minimal transparency.
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?
The description is a single sentence, which is concise but too brief for a tool with 10 parameters and no annotations. It lacks critical information and does not front-load important details; under-specification is not efficiency.
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?
Given the tool's complexity (10 params, no annotations, no output schema), the description is incomplete. It fails to explain optional parameters, constraints (e.g., mutual exclusivity of data/url), return behavior, or prerequisites. Agents would lack guidance for correct invocation.
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 description coverage is low (40%), and the description adds value by clarifying that 'data' is base64 and 'url' is a URL, and that only one should be provided. However, it does not explain the other 6 parameters (mentions, replyTo, etc.), leaving gaps.
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?
The description states 'Send a voice message (PTT)', clearly indicating the action and resource. It specifies the media type (voice/PTT) but does not differentiate from sibling 'whatsapp_send_audio', which could cause confusion. Thus clear but lacks sibling distinction.
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?
The description only advises to 'Provide either data (base64) or url', which is partial parameter guidance. It provides no context on when to use this tool over alternatives like 'whatsapp_send_audio' or 'whatsapp_send_text', nor when not to use it.
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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