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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is covered. The description adds that alignment targets 'detected singing timing', implying a prior analysis step, but it does not say whether the alignment is persisted, what happens if timing has not been detected, or whether existing alignment is overwritten (idempotentHint is false).

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 no filler. It is efficient, though its brevity is part of why the usage and parameter gaps remain unfilled.

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?

With three parameters, two required, low schema coverage, and no output schema, the description carries most of the explanatory burden and does not meet it. An agent still lacks the expected result shape, the role of music_id, and the preconditions for alignment.

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 only 33%: only project_id is documented, while lyrics and music_id are bare. The description gestures at both ('supplied lyric text', 'selected track') but never explains that music_id is optional or what track is used when it is omitted, so it does not compensate for the coverage gap.

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 ('Aligns supplied lyric text to detected singing timing on the selected track'), which is much more informative than the title alone. It does not, however, distinguish itself from nearby siblings such as get_syllables, get_words, get_transcript, or add_captions, which an agent could plausibly confuse with lyric alignment.

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?

There is no explicit when-to-use guidance, no prerequisites (e.g. that singing timing must first be detected/analyzed), and no named alternative. The agent must infer that this is the tool for syncing lyrics to vocals rather than captioning or syllable extraction.

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