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

Annotations already declare readOnly/idempotent/non-destructive, and the description reinforces this with 'returns steps and a link and creates nothing.' Beyond that it discloses what the person must actually do (create an account, sing ~a minute, add a song they have rights to use) and the voice-ownership restriction, which no structured field conveys.

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?

The purpose and outcome are front-loaded, followed by the workflow and the exclusion. Every sentence is relevant, though the signup/sing/upload sequence is slightly more procedural detail than an agent needs before invoking.

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 an output schema present and full schema descriptions, the description needn't explain return values, and the annotation set covers the safety profile. It is essentially complete, only omitting any hint about what the optional inputs are for.

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 description coverage is 100% and all three parameters are optional with clear per-field descriptions, so the schema carries the load. The description never references language, occasion, or song_title, so it adds no meaning beyond the schema — baseline 3.

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 description leads with a specific verb and outcome: explain how to hear a song in one's own voice with Tera Studio and give them the start link. It is also clearly not a music-analysis operation like the sibling find_song_key tools, so an agent can distinguish it without opening a 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?

It gives concrete triggering intents — hear yourself sing, make a cover in your own voice, turn a song into a gift — plus an explicit exclusion: not for celebrity or other people's voices. It stops short of naming alternative tools or the case where a different path (e.g. key/tempo tools) is the right call, so it's a 4 rather than a 5.

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