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

Annotations only declare readOnlyHint and openWorldHint; the description adds the things an agent actually needs: authentication is mandatory (anonymous callers unsupported), tier-based quotas (2 scans/day on free, unlimited on Pro/Premium), partial result gating on free accounts, and the presence of skip reasons for invalid or unavailable links. That is substantial disclosure beyond the annotations.

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?

Three sentences, front-loaded with the purpose, then the alternative, then the return shape and account requirements. Every sentence carries information, but the final sentence packs tier limits, auth, and optional-parameter behavior together, making it denser than ideal.

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, and the description compensates by stating what comes back (playlists ranked by bot-risk score, with skip reasons for bad links) and how the output changes by account tier. Combined with the 100%-covered input schema, an agent has everything needed to call this 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?

Schema coverage is 100%, so the baseline is 3. The description still adds value by explaining that artistName, trackName and distributor are not just labels but trigger drafted reply text, and that this text only appears 'once the report is unlocked' — a conditional the schema does not convey.

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 and resource ('Scores every Spotify playlist') plus the triggering context (distributor flag for artificial streaming) and the input shape (the full list pasted from Spotify for Artists). It also explicitly names the sibling check_playlist as the single-link alternative, so the agent can distinguish the two without opening either 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?

Gives an explicit use condition ('a batch of up to 50 links'), an explicit exclusion with an alternative ('for one playlist, use check_playlist, which also works anonymously'), and a precondition ('Requires a signed-in account'). Nothing about when to pick this tool is left to inference.

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