Wrapped-style summary

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

Annotations already declare readOnlyHint=true, idempotentHint=true and openWorldHint=false, so the safety profile is covered. The description adds real behavioral context beyond that: valid ranges are gated by list_wrapped_ranges and other ranges 'may be refused', which is a precondition an agent would otherwise learn only by failing.

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?

Two sentences, purpose and payload front-loaded, with the enumeration doing real work because there is no output schema. The constraint sentence follows the payload, and nothing is repeated from the name or annotations.

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?

With no output schema, the description takes on the job of describing return content and does so thoroughly, and it covers the input constraint. The gap is a few details on return shape (ordering, volume of data) and exact accepted range form, which are minor for a read-only, idempotent summary tool.

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 0%, so the burden falls on the description; it partly compensates by tying 'from'/'to' to ranges produced by list_wrapped_ranges and by requiring a 'finished' range. It never states the expected format or boundary inclusivity, which the pattern alone conveys only implicitly.

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?

States a specific, recognizable artifact (a Wrapped-style summary) over a bounded resource (a finished date range) and enumerates exactly what it returns: minutes, top artists/songs/albums, biggest day, streak, per-month leaders, discoveries, listening age. This breadth clearly separates it from narrow siblings like top_artists or top_tracks, so an agent can pick it without opening the schema.

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?

'Use a range from list_wrapped_ranges; others may be refused' gives an explicit precondition and names the sibling that supplies valid inputs, plus a soft exclusion for unlisted ranges. There is no explicit statement of when a caller should prefer top_artists/search instead for a narrower question, which keeps it short of a 5.

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