x402_transcribe_audio

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

With no annotations provided, the description comprehensively covers: charging behavior (charged on download, refusals still charged), performance characteristics (30-120s, CPU-based, serial queue), format support, hard limits (25MB/10min), and authentication requirements. Critical behavioral traits fully disclosed.

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?

Information-dense with logical flow: purpose → pricing → limits → timing → auth → returns. Six sentences with zero waste given the operational complexity (payment API). Slightly dense but appropriately front-loaded with critical cost/pricing info.

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 no output schema, description explicitly lists all return fields (transcript, language, confidence, duration, timestamps). Covers all operational necessities for a paid API: auth, pricing, file constraints, and async timing expectations. Complete for the complexity level.

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 coverage is 100%, establishing baseline 3. Description reinforces concepts (e.g., 'auto language detection' aligns with optional language param, 'word timestamps' referenced in returns) but does not add significant semantic depth beyond well-documented schema fields.

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?

Clear specific verb ('Transcribe'), resource ('audio file'), implementation detail ('faster-whisper'), and key feature ('auto language detection'). Unambiguous scope distinguishes it clearly from sibling tools like convert_file or scrape_url.

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?

Provides explicit prerequisites (X402_PRIVATE_KEY for paid mode), cost model ($0.05 USDC), and free test alternative. Lacks explicit comparison to specific sibling alternatives, but clearly delineates between free test and paid usage modes.

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