Track

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

With annotations present the bar is lower, and the description adds genuinely useful context the annotations cannot: paid API credit consumption, the confirm=true gate, and the clarification that this is a read-like POST that does not publish to social platforms. That last sentence usefully explains why readOnlyHint=false even though the operation is a retrieval, though it stops short of describing rate limits or failure modes.

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, front-loaded with purpose and followed by cost/confirmation caveats; nothing is padding. The second sentence is dense but each clause (credits, confirm flag, no social publishing) carries distinct information the agent needs.

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?

There is no output schema, so the description correctly compensates by naming the returned fields, and it covers cost and confirmation preconditions. What remains thin is discovery guidance (how to obtain an id) and any notion of error or empty-result behavior, which are minor for a single-resource lookup.

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% and each parameter (id, url, account, confirm) is already documented in the schema, so the baseline is 3. The description reiterates the id-or-URL duality and the confirm requirement, adding no syntax, format, or constraint detail beyond what the schema already states.

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 verb ('Retrieves') and a specific resource ('a Spotify track by its id or URL'), then enumerates the returned payload (metadata, artists, album info, duration, playability, sharing details). This clearly separates it from sibling lookups like spotify_artist, spotify_album, spotify_playlist and apple_music_track/soundcloud_track without ambiguity.

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?

It gives one concrete precondition ('requires confirm=true') and warns about credit consumption, which is real usage guidance. However, it never says when to reach for this tool versus spotify_search (to discover an id) or spotify_album/spotify_artist for adjacent resources, leaving the routing decision to inference.

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