agent402-mcp

transcribe

audio.transcribe

Read-onlyIdempotent

Transcribe audio files from a URL into text, with optional speaker labels and word timestamps for meetings or interviews.

Instructions

[$0.030/call, wallet required] Transcribe audio to text with the gpt-transcribe model. Provide a URL to an audio file (mp3, wav, m4a, etc.) and get back the transcript. Add diarize:true for speaker labels, word timestamps and a language confidence score (the scribe-v2 model, same price). No API key needed; pay per call via x402. Max 4 minutes of audio, 25 MB file size; /api/transcribe-pro takes the same models to 10 minutes.

Input Schema

TableJSON Schema

Name	Required	Description
`url`	Yes	URL of the audio file to transcribe (mp3, wav, m4a, ogg, flac, webm)
`diarize`	No	true: transcribe with the scribe-v2 model and add speaker labels and word timestamps (`words`, `speakers`) and `language_confidence` (0 to 1, the model's confidence in the detected language). Same price and cap. Default false
`language`	No	Optional ISO-639-1 language code (e.g. 'en', 'es', 'fr') for better accuracy

Output Schema

TableJSON Schema

Name	Required	Description	Default
`text`	Yes
`model`	No
`duration`	No
`language`	No
`provider`	No

Schema Changelog

Changes observed during successful MCP inspections.

Changed1 schema field changedv2.7.0Oct 16, 2026

changedInput schema / properties / diarize / description

Previous value: -"true: transcribe with the scribe-v2 model and add speaker labels and word timestamps (`words`, `speakers`). Same price and cap. Default false"New value: +"true: transcribe with the scribe-v2 model and add speaker labels and word timestamps (`words`, `speakers`) and `language_confidence` (0 to 1, the model's confidence in the detected language). Same price and cap. Default false"

Changed1 schema field changedv2.4.1Oct 13, 2026

addedInput schema / properties / diarize

Added value: +{
+  "description": "true: transcribe with the scribe-v2 model and add speaker labels and word timestamps (`words`, `speakers`). Same price and cap. Default false",
+  "type": "boolean"
+}

Addedv2.3.0Sep 2, 2026

TDQS

A4.6/5.0

Behavior5/5

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

Annotations only cover the safety profile (readOnly, idempotent, non-destructive, open-world). The description adds the facts an agent actually needs before calling: cost ($0.030/call), the wallet/x402 payment requirement with no API key, and the hard 4-minute/25 MB caps. It also discloses that diarize silently switches to a different model (scribe-v2) at the same price, which is not inferable from annotations.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Conciseness4/5

Is the description appropriately sized, front-loaded, and free of redundancy?

Front-loaded with the price and payment requirement in brackets, then purpose, options, and limits in a single dense paragraph. Nearly every clause earns its place; only the model/price restatement of the diarize option is mildly redundant with the schema.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Completeness5/5

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With an output schema present the description needn't explain return values, and it still covers payment model, cost, size/duration limits, the upgrade path for longer audio, and the optional diarize/language knobs. Nothing an agent needs to invoke this correctly 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 description coverage is 100%, so all three parameters (url, diarize, language) are already fully documented in the schema, including the diarize output fields and the 'same price and cap' note. The description repeats that information rather than adding new semantics such as accepted URL schemes or language fallback behavior, so the baseline of 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+resource ('Transcribe audio to text') and names the underlying model (gpt-transcribe), making the tool's identity unambiguous. No sibling tool in the list performs transcription, so no differentiation is required, but the scope is still precise.

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

Usage Guidelines5/5

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

Gives explicit routing conditions: use this tool for audio up to 4 minutes / 25 MB, otherwise /api/transcribe-pro covers up to 10 minutes, and set diarize:true when speaker labels are needed. An agent can decide between the two endpoints without inference.

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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