update_track

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

No annotations are supplied, so the description carries the full behavioral burden, and it does not say whether omitted/null fields are left unchanged or reset to defaults — a critical semantic for a tool where every optional parameter defaults to null. It also omits permission/auth requirements, whether the change is undoable, and whether the project must be open.

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?

Front-loaded and compact: the field list with value ranges is tight and skimmable. The Japanese sentence is a straight duplicate that adds length without adding information, though it may serve bilingual agents.

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 nine-parameter mutation with zero schema description coverage, no annotations, and no output schema, the description is thin: partial-update semantics, identifier format for `track`, and valid value sources (e.g., list_singers/list_phonemizers) are all unaddressed. It is enough to guess the intent but not enough to call it safely.

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 0%, and the description compensates well by naming eight of the nine fields plus units and bounds the schema lacks: volume in dB (-24..12) and pan (-100..100). It still does not explain the required `track` parameter (index vs. ID) or whether `singer`/`phonemizer`/`renderer` take names or identifiers, keeping it below 5.

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 opens with a specific verb+resource ("Change a track") and enumerates the mutable fields, so an agent knows exactly what the tool affects. It does not distinguish itself from close siblings such as update_part or ustx_set_track_singer, so a 4 rather than a 5.

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?

Listing mutable fields implies when to reach for it (any track edit), but there is no explicit when-to-use guidance, no statement of prerequisites (e.g., a project must be open), and no pointer to alternatives like ustx_set_track_singer for singer-only edits. Usage is inferable only.

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