play

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

No annotations exist, so the description carries the full behavioral burden, and it omits key traits for a playback tool: whether the call blocks until playback finishes or returns immediately, what happens on a second invocation while playing, and whether OpenUtau must already be running (siblings like launch_openutau and openutau_status suggest a dependency).

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 English sentence is compact and front-loads the key scoping. However, the Japanese sentence duplicates the identical information with no added detail, and the 'optionally ... optionally ...' phrasing buries the defaults, so part of the text doesn't earn its place for a schema-reading agent.

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 tool with three undocumented parameters, no annotations, and no output schema, the description is thin: it never states the return value (e.g., confirmation of started playback), the async/blocking model, or prerequisites related to the OpenUtau host application that sibling names imply.

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%, so the description must do the work, and it does partially: 'from tick' establishes tick as a start position, end_tick as an optional stop, and track as limiting playback to one track. It does not clarify what null tick means (project start vs. current position) or the unit/semantics of a negative or out-of-range tick, leaving gaps at 0% schema 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?

The description uses a specific verb and resource ('Start playback') and scopes it: start position via tick, optional stop at end_tick, optional single-track restriction. This distinguishes it from the sibling 'pause' well enough to select correctly, though it never explicitly contrasts the two.

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?

Usage is implied only — you infer you call this when you want audio playback to begin. There is no statement about when not to use it, what to do if playback is already running, or how it relates to the 'pause' sibling.

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