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

Adds substantial behavior beyond the readOnly/idempotent annotations: jobs are readable for 7 days, the playUrl is valid for roughly an hour, a deleted song surfaces as status 'deleted', and wait blocks about 50 seconds. These are non-obvious operational constraints an agent could not derive from annotations or schema.

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 but well ordered: resource and identity first, return payload second, usage trigger and limits last, endpoint path closing it out. The long nested parenthetical listing song fields is somewhat crammed, but every clause carries information.

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, so the description carries the full burden of describing return values, and it does: status, per-song fields, playUrl lifetime, deleted-song representation, and the 7-day read window. Nothing an agent needs in order to call or interpret the result is missing.

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 baseline is 3; the description earns an extra point by explaining what wait actually does in the calling flow ('wait: true waits up to ~50 s') and by pinning jobid to the value returned by the create/split tools, adding provenance the schema does not.

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 (retrieve a song or stem-split job by jobid) and enumerates the payload shape: status, songs with songId/title/model/duration/mp3 link/playUrl/cover, or stem tracks. That level of specificity separates it cleanly from acemusic_list_jobs and acemusic_get_song 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 trigger: 'Use it after acemusic_create_song or acemusic_split_stems returned a jobid still processing', which is exactly the condition that selects this tool over its siblings. It stops short of stating when not to use it (e.g., to enumerate jobs, use list_jobs), so it is clear context but not full routing.

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