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

Annotations cover read-only, idempotent, non-destructive safety. Beyond that, the description adds valuable behavioral detail: invalid ISRCs are listed and skipped, results include an as_of snapshot date, and it explicitly disclaims legal advice/ownership. It does not mention rate limits or performance, which would complete the picture.

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?

Well front-loaded: batch scope, output verdicts, and the disclaimer are stated efficiently. However, the enumeration of return fields (verdicts, confidence, MLC song code, unclaimed share, summary, next steps, as_of, ISWCs, writers) is somewhat dense and long for a description when an output schema exists.

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 read-only batch lookup with an output schema and annotations, the description covers scope, expected outputs, edge cases (invalid ISRCs), and a legal caveat. It is nearly complete but lacks explicit routing guidance to sibling tools, which would make it fully self-contained.

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% and the schema itself documents ISRC format, max 50, and the split-catalogue guidance. The description repeats the batching constraint but adds no new syntax or semantic detail beyond the schema, so baseline 3 is appropriate.

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+resource: 'Catalogue registration check (batch ISRC lookup)' against The MLC. It clearly distinguishes its batch scope (up to 50) from the singular sibling lookup_recording.

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?

Implies the use case ('finds recordings whose music royalties may be unmatched or unclaimed') and notes batching for larger catalogues, but never explicitly states when to use this tool vs. lookup_recording (its single-record sibling) or request_full_report.

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