ustx_set_vibrato

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

No annotations exist, so the description carries the full burden. It usefully discloses the bulk-application behavior when indices are omitted and the length>0 activation rule, but stays silent on whether existing vibrato fields are overwritten, whether length=0 clears vibrato entirely, and what the mutation returns.

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?

Two compact sentences with the scope constraint front-loaded ahead of the behavioral rule; the bilingual duplication is intentional and the content is not padded. Nothing is wasteful, though the sentence order could surface the activation rule more sharply.

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 four-parameter mutation with no annotations and no output schema, the definition covers the biggest gotcha (omitted indices = all notes) but leaves the write semantics, overwrite behavior, and non-vibrato parameters underspecified.

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?

Outer schema coverage is 0%: path, part, and the vibrato object have no descriptions, and the description only clarifies indices and the length field's threshold. It adds real value on that one trap but leaves the semantics of path, part, and the remaining vibrato fields to the agent's inference.

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 and resource ("Set vibrato fields on notes in a .ustx file") and adds a scope qualifier ("no indices = all notes"). It does not explicitly distinguish itself from neighbors like set_pitch or ustx_set_tempo, but the vibrato-specific wording is unambiguous.

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 parenthetical "no indices = all notes" and "length > 0 turns vibrato on" give concrete conditions of use, but there is no statement of when to prefer this over related tools (e.g. set_pitch, set_note_expression) and no prerequisites or exclusions.

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