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

Beyond the annotations (readOnly, idempotent, openWorld), the description discloses genuinely non-obvious behavior: credit attribution.line, the requirement to ask the user when ambiguity.state is not none, and that untrusted_text is display-only (a prompt-injection guard). It also implies the onward key (clusterId) and batch row metadata, which no annotation covers.

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?

Dense, front-loaded and organized into Purpose / Use / Inputs / Returns / Cautions lines, with no filler sentences. The telegraphic shorthand ('Credit attribution.line') is efficient but slightly terse for an uninitiated agent.

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 6 parameters, low schema coverage, and no output schema, the description carries real burden and largely meets it by describing the return shape (data.results[], clusterId, query_index/matched/confidence). The undocumented `fuzzy` flag and the `year` field (only noted as unused in the schema) are the remaining holes.

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 only 33%, and the description compensates well by spelling out the exclusive input modes, the batch cap (≤ 25), and the limit range with default. The `fuzzy` parameter is documented nowhere in the description and has no schema description, leaving one real gap.

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 opening sentence names a specific verb and resource and enumerates the three lookup modes (title, artist+track, batch), plus the facts returned (release facts, durations, cluster_id). It does not explicitly contrast with siblings like search_catalog or resolve_artist, so an agent must infer that this is track-level rather than catalog-wide search.

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: the user names a song; a tracklist' gives concrete triggering contexts, and the input line clarifies that the three input modes are mutually exclusive alternatives. It stops short of naming when-not conditions or naming a sibling to use instead, so it is clear context without exclusions.

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