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

Annotations only declare it is a non-destructive, open-world write. The description adds the operationally critical detail that this runs as a job: the call blocks for about two minutes, may return queued/running instead of a result, and in that case the agent must poll get_generation with its id. That is exactly the behavior an agent cannot infer from annotations.

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?

Three tight sentences: purpose first, sibling/cost differentiation second, async mechanics third. Nothing is padding and the most important constraint (job may not finish) is not buried.

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 6-parameter, nested-schema generation tool with no output schema, the description covers the async lifecycle, the polling fallback, and the cost/vendor distinction from the nearest sibling. Combined with the fully documented schema, an agent has everything needed to call and follow up correctly.

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 100%, so the schema already documents tier, model, params, provider and title_id, including the nested params object and the tier-cancelling warnings. The description adds no parameter-level meaning beyond that, so the baseline 3 applies.

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 ('Generate music (a loop or a short track)') and immediately scopes the output type. It also names and rules out the nearest sibling by explaining that generate_audio is speech, so an agent can route without opening either schema.

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?

Explicitly distinguishes this tool from generate_audio on both vendor path and price, which is real routing guidance. It does not state when-not to use it (e.g. for voiceover or longer tracks), so it stops short of a full when/alternatives rule set.

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