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HubVibe: Pay-per-Call Agent Tools: Web Search, Email Verify, KYC Screening, Stocks, Crypto, News

Text to speech

hubvibe_speech_synthesize
Read-onlyIdempotent

Text to speech (TTS): convert text to natural spoken MP3 audio with Google Cloud Text-to-Speech, returned as base64. Use it for voice replies, narration, audio versions of text and accessibility. Input: text; optional voice name. $0.25 per call. Returns: text_chars, voice, audio_base64, mime_type.

Input Schema

TableJSON Schema
NameRequiredDescriptionDefault
textYes
voiceNoe.g. en-US-Standard-C. Optional.
languageNoOptional BCP-47 language tag (en, ja, ko, pt-BR): the human-readable strings of the result (notes, details, reasons) are translated into this language; data, codes, numbers and URLs are untouched. Default: as produced.

Output Schema

TableJSON Schema
NameRequiredDescriptionDefault
resultYes
statusYes
workerYes
price_usdYes
provenanceYes
receipt_idYes
attributionNo
receipt_urlYes
billing_warningNo

Schema Changelog

Changes observed during successful MCP inspections.

  1. Changed23 schema fields changed
    • removedOutput schema / description
      Removed value: -"The 200 body of every paid /work call. `result` is the worker's own output (its schema is per route); everything else is the same on every /work route. A receipt for the job is at `receipt_url`."
    • removedOutput schema / properties / attribution / description
      Removed value: -"Present only when the result's text was machine-translated: the credit to show with it."
    • removedOutput schema / properties / attribution / items / description
      Removed value: -"A credit."
    • removedOutput schema / properties / attribution / items / properties
      Removed value: -{
      -  "text": {
      -    "description": "Credit.",
      -    "examples": [
      -      "Translated by Google"
      -    ],
      -    "type": "string"
      -  },
      -  "url": {
      -    "description": "Link.",
      -    "examples": [
      -      "https://translate.google.com"
      -    ],
      -    "type": "string"
      -  }
      -}
    • removedOutput schema / properties / attribution / items / required
      Removed value: -[
      -  "text",
      -  "url"
      -]
    • removedOutput schema / properties / attribution / items / type
      Removed value: -"object"
    • removedOutput schema / properties / billing_warning / description
      Removed value: -"Present only when the charge was recorded with a caveat."
    • removedOutput schema / properties / billing_warning / examples
      Removed value: -[
      -  "settlement pending"
      -]
    • removedOutput schema / properties / price_usd / description
      Removed value: -"What this call cost, in USD."
    • removedOutput schema / properties / price_usd / examples
      Removed value: -[
      -  0.02
      -]
    • removedOutput schema / properties / provenance / description
      Removed value: -"How the result was produced: which providers ran and how long each took."
    • removedOutput schema / properties / provenance / properties
      Removed value: -{
      -  "attempts": {
      -    "description": "Provider attempts made, including retries and failovers.",
      -    "examples": [
      -      1
      -    ],
      -    "type": "integer"
      -  },
      -  "elapsed_ms": {
      -    "description": "Wall-clock milliseconds for the whole job.",
      -    "examples": [
      -      340
      -    ],
      -    "type": "integer"
      -  },
      -  "providers_used": {
      -    "description": "Providers that served the job.",
      -    "examples": [
      -      [
      -        "coinbase-advanced-trade-public"
      -      ]
      -    ],
      -    "items": {
      -      "description": "Provider name.",
      -      "examples": [
      -        "coinbase-advanced-trade-public"
      -      ],
      -      "type": "string"
      -    },
      -    "type": "array"
      -  },
      -  "steps": {
      -    "description": "Every step the job ran, in order.",
      -    "items": {
      -      "description": "One step of the job.",
      -      "properties": {
      -        "ms": {
      -          "description": "Milliseconds the step took.",
      -          "examples": [
      -            312
      -          ],
      -          "type": "integer"
      -        },
      -        "ok": {
      -          "description": "Whether the step succeeded.",
      -          "examples": [
      -            true
      -          ],
      -          "type": "boolean"
      -        },
      -        "provider": {
      -          "description": "Provider that served the step.",
      -          "examples": [
      -            "coinbase-advanced-trade-public"
      -          ],
      -          "type": "string"
      -        },
      -        "reason": {
      -          "description": "Failure reason, on a failed step.",
      -          "examples": [
      -            "provider_timeout"
      -          ],
      -          "type": "string"
      -        },
      -        "step": {
      -          "description": "Step name inside the worker.",
      -          "examples": [
      -            "quote"
      -          ],
      -          "type": "string"
      -        }
      -      },
      -      "required": [
      -        "step",
      -        "ok",
      -        "ms"
      -      ],
      -      "type": "object"
      -    },
      -    "type": "array"
      -  }
      -}
    • removedOutput schema / properties / provenance / required
      Removed value: -[
      -  "steps",
      -  "providers_used",
      -  "attempts",
      -  "elapsed_ms"
      -]
    • removedOutput schema / properties / receipt_id / description
      Removed value: -"Receipt id for this job."
    • removedOutput schema / properties / receipt_id / examples
      Removed value: -[
      -  "rcpt_9f1c2b3a4d5e6f70"
      -]
    • removedOutput schema / properties / receipt_url / description
      Removed value: -"Where to fetch the machine-readable receipt (free, no payment)."
    • removedOutput schema / properties / receipt_url / examples
      Removed value: -[
      -  "/work/receipts/rcpt_9f1c2b3a4d5e6f70"
      -]
    • removedOutput schema / properties / result / properties
      Removed value: -{
      -  "audio_base64": {
      -    "description": "The audio, base64.",
      -    "examples": [
      -      "UklGRi4AAABXQVZF..."
      -    ],
      -    "type": "string"
      -  },
      -  "mime_type": {
      -    "description": "Audio MIME type.",
      -    "examples": [
      -      "audio/mpeg"
      -    ],
      -    "type": "string"
      -  },
      -  "text_chars": {
      -    "description": "Characters synthesised.",
      -    "examples": [
      -      58
      -    ],
      -    "type": "integer"
      -  },
      -  "voice": {
      -    "description": "Voice used.",
      -    "examples": [
      -      "en-US-Neural2-C"
      -    ],
      -    "type": "string"
      -  }
      -}
    • removedOutput schema / properties / result / required
      Removed value: -[
      -  "text_chars",
      -  "voice",
      -  "audio_base64",
      -  "mime_type"
      -]
    • removedOutput schema / properties / status / description
      Removed value: -"Present only on a delivered result."
    • removedOutput schema / properties / worker / description
      Removed value: -"Catalog name of the worker that ran."
    • removedOutput schema / properties / worker / examples
      Removed value: -[
      -  "market.quote"
      -]
    • removedOutput schema / title
      Removed value: -"speech.synthesize response"
  2. Changed1 schema field changed
    • addedOutput schema / properties / attribution
      Added value: +{
      +  "description": "Present only when the result's text was machine-translated: the credit to show with it.",
      +  "items": {
      +    "description": "A credit.",
      +    "properties": {
      +      "text": {
      +        "description": "Credit.",
      +        "examples": [
      +          "Translated by Google"
      +        ],
      +        "type": "string"
      +      },
      +      "url": {
      +        "description": "Link.",
      +        "examples": [
      +          "https://translate.google.com"
      +        ],
      +        "type": "string"
      +      }
      +    },
      +    "required": [
      +      "text",
      +      "url"
      +    ],
      +    "type": "object"
      +  },
      +  "type": "array"
      +}
  3. Changed1 schema field changed
    • addedInput schema / properties / language
      Added value: +{
      +  "description": "Optional BCP-47 language tag (en, ja, ko, pt-BR): the human-readable strings of the result (notes, details, reasons) are translated into this language; data, codes, numbers and URLs are untouched. Default: as produced.",
      +  "maxLength": 35,
      +  "pattern": "^[A-Za-z]{2,3}(-[A-Za-z0-9]{2,8})*$",
      +  "type": "string"
      +}
  4. Changed1 schema field changed
    • changedOutput schema / description
      Previous value: -"The 200 body of every paid /work call. `result` is the worker's own output (its schema is per route); everything else is the same on all 38 routes. A receipt for the job is at `receipt_url`."New value: +"The 200 body of every paid /work call. `result` is the worker's own output (its schema is per route); everything else is the same on every /work route. A receipt for the job is at `receipt_url`."
  5. Added

TDQS

A3.8/5.0
Behavior4/5

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

The annotations already cover safety (readOnly, idempotent, non-destructive). The description adds valuable context beyond annotations: external service (Google Cloud TTS), output format (MP3 base64), cost ($0.25 per call), and returned fields. It does not mention rate limits or input constraints.

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?

The description is front-loaded with purpose, then usage contexts, then input/output and cost. It is tightly written with every sentence contributing necessary information and zero redundancy.

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?

An output schema exists and annotations cover safety, so the description need not repeat those. It supplies cost, usage scenarios, and output format, making it largely complete. The only notable gap is the omission of the 'language' parameter, which could mislead an agent about available inputs.

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

Parameters2/5

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

The description lists only 'text' and 'optional voice name', omitting the 'language' parameter entirely. It adds no semantic detail beyond what the schema already provides for the two parameters it does mention, failing to compensate for the 67% schema description coverage.

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

Purpose4/5

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

The description states a specific verb and resource: 'convert text to natural spoken MP3 audio with Google Cloud Text-to-Speech'. It clearly identifies the tool as TTS, but does not explicitly distinguish it from the sibling hubvibe_speech_transcribe or name any alternative.

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?

It gives clear usage contexts: 'voice replies, narration, audio versions of text and accessibility'. However, it provides no when-not-to-use guidance or explicit alternatives, leaving the agent to infer boundaries.

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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