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

No annotations are supplied, so the description carries the full burden and does so well: it discloses the price ($0.10 USDC on Base via x402), notes that the live 402 challenge is authoritative, and states explicitly that the tool never pays, never touches private keys, and never holds funds. It also discloses a licensing behavior that is unusual and consequential, namely that resale of the data output is permitted at the reseller's own price.

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?

Four dense sentences, each earning its place: purpose and pricing first, then the two-phase flow, then the safety and resale terms. Some of the payment mechanics are restated in the 'payment' parameter description, a minor redundancy, but the main body itself is tight and front-loaded.

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 paid, two-phase x402 tool with no output schema, the description covers payment, safety, and licensing thoroughly. The remaining gap is the shape of the returned data: it says only that the data comes back 'in the tool result' and never sketches what a track or quote record contains, which an agent would otherwise get from an output schema.

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 100%, with mood enumerations and the 1-240 minute bounds fully documented in the schema, so the baseline is 3. The description reinforces the mood+minutes semantics and the phase semantics of 'payment', but adds little beyond what the schema descriptions already say.

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 verb and resource: a track list built from a mood plus a minutes budget, with per-track sync-license quotes and terms. It also draws a sharp line ('Data only: quotes are not licenses'), which disambiguates it from quoting a real license. It never names a sibling tool such as qm_sleep_queue or qm_sleep_recommend, so the boundary against those closest neighbors is left to inference.

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 two-phase invocation is spelled out precisely: the first call without 'payment' returns live payment requirements, and the second call with the base64 x402 payload returns the data. This is clear context for how to use the tool. What is missing is routing guidance against siblings, such as when to choose this mood-based playlist rather than qm_sleep_recommend or qm_sleep_queue.

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