react_timeline_sequence_lyric_state

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

Annotations already declare readOnlyHint=true and openWorldHint=false, so the safety profile is covered. The description adds one genuinely useful piece of context — the dependency on an 'optional' audition API, implying the call may be unavailable — but it does not say what happens if that API is absent or what 'active' means at boundary times.

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 tight sentence with the verb and scope front-loaded and no filler. It is appropriately sized, though the brevity comes at the cost of the missing parameter detail noted above.

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?

An output schema exists, so return values need no explanation, but the input is a nested object with four undocumented fields including a required 'duration' whose role is opaque. For a tool with nested params, 0% schema coverage, and a conditional dependency on an optional API, one sentence leaves real gaps.

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%, so the description must carry the burden. It only loosely maps 'source time' to the required 'seconds' field and 'lyric/word' to lines/words; the required 'duration' parameter and the line/word start-end/label semantics are entirely unexplained, and the nested structure is not addressed at all.

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 states a specific verb and resource: 'Read active lyric/word states at a source time.' An agent can tell this is a point-in-time query over lyric/word timing data. It does not name a sibling to differentiate from, but the sibling list contains no other lyric-state tool, so the ambiguity cost is low.

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?

'using the timeline's optional lyric-audition API' implies a precondition (the API may not be enabled) and hints that this is a read-only query at a given playback time. There is no explicit statement of when to call this versus the beat-clock or beat-grid siblings, and no when-not-to-use guidance.

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