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

Annotations already declare readOnly=false, idempotent=false, destructive=false, so the mutation profile is covered. The description adds real value beyond that: the replacement semantics of credits and the validation rule (at least one songwriter, performer and producer). The 'real people, ask the artist, never invent' line is strong anti-hallucination guidance. It stops short of describing what happens to prior credits or error behavior.

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 action, then the requirement, then the ethical caution. Each sentence earns its place and nothing is padded, though the closing line is advisory rather than definitional.

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?

No output schema exists, but the description conveys the essential context an agent needs: that this replaces existing credits and that release submission depends on having all three roles. Combined with the rich schema, it is nearly complete; only the fate of replaced credits and failure modes are unstated.

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 75%, so the schema already documents artist, credits and dry_run in detail, including role/performer_type/instrument constraints. The description only restates that credits is 'this list' and adds no syntax or format detail beyond the schema. Baseline 3 is appropriate when structured fields carry the load.

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 concrete verb and resource: 'Replace a track's song credits with this list.' That is specific enough to identify the operation. It does not, however, distinguish itself from close siblings like set_track_artists or update_track, leaving the agent to infer the boundary between 'artists' and 'credits'.

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?

The description supplies a clear precondition/context ('before its release can be submitted') and hints at using dry_run via the schema. But it never names an alternative or an explicit when-not condition, so routing against set_track_artists/update_track 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.