ustx_set_track_singer

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

No annotations are supplied, so the description carries the full burden. It usefully discloses the phonemizer precedence rule (given > voicebank default > Japanese presamp), which is real behavioral context. But for a file-mutating tool it omits whether changes are written in place, whether a separate save is needed, and failure behavior for an invalid track.

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?

A single front-loaded sentence with the key behavior (phonemizer precedence) parenthetically embedded, plus a Japanese mirror. The bilingual duplication is token-heavy but introduces no ambiguity.

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 mutation tool on a project file with no annotations, no output schema, and 0% schema coverage on four parameters, the description is thin. It should at least state what 'track' identifies, whether the change is persisted to disk, and failure modes; the phonemizer precedence is the one strong element.

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 0% — all four parameters are bare titles. The description compensates for the most important gap by explaining the phonemizer defaulting chain and the singer concept. However, 'track' (index vs. name) and 'path' (absolute/relative, existing file) remain unexplained, which is a real gap at 0% coverage.

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 (set) and resource (singer/phonemizer of a track in a .ustx file), with the bilingual line reinforcing the scope. It is clearly distinguishable from siblings like ustx_set_tempo or ustx_set_vibrato, which set different track properties.

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?

No when-to-use/when-not guidance and no named alternatives or prerequisites. It does not say the file must exist, that the track index must be valid, or that this is typically called after ustx_add_track.

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