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

With no annotations provided, the description carries the full burden and does so well: it discloses the $1.00 USDC micropayment, the one-time 15-minute link expiry, the language options, the returned fields, and the error behavior for unknown ids. This is substantial behavioral context beyond the name and schema.

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 compact and front-loaded with the most important facts: payment, resource type, and link expiry. It then covers the required input and the return/error behavior. Slightly dense, but every sentence carries useful information.

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?

For a simple one-parameter tool with no output schema and no annotations, the description is complete: it describes the required id, how to obtain valid ids, the output fields, the payment, the link's time limit, and the error case. An agent has enough information to invoke this tool correctly.

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?

The schema already fully documents the single parameter with a type, example ('AU-05'), and required flag, so baseline 3 applies. The description reinforces that the id must come from list_catalog and warns about unknown-id errors, but adds no new format or type detail beyond the schema.

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 a specific action and resource: it returns a one-time, 15-minute download link for a guided-relaxation MP3, and distinguishes this from sibling tools by the audio/track focus and the paid x402 micropayment. It also names the exact source of valid ids (list_catalog), making the tool's role unambiguous.

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 gives explicit usage context: call list_catalog first to obtain valid ids and set the required 'id' parameter. It doesn't explicitly compare this tool to siblings or state when not to use it, but the audio-specific purpose and clear prerequisite make the intended usage clear.

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