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

Annotations cover idempotency and open-world reach, but the description adds the crucial behavioral facts they don't: it spends credits from the wallet, requires user confirmation, and returns asynchronously with a generationId rather than the finished artifact.

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 sentences, front-loaded with the cost warning, each carrying a distinct operational fact (cost/consent, mode choice, async return). No filler.

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?

Despite no output schema, the description explains the return shape (generationId) and the polling path via get_generation, and covers the consent/credit prerequisite — everything needed to invoke and follow through.

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 all five parameters (including the mode enum and idempotencyKey semantics) are already documented. The description only echoes the sound_effect mode, adding no parameter detail beyond the schema — the baseline 3.

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 ('Generates a song, or a sound effect with mode "sound_effect"') and references related siblings (estimate_credits, get_generation), so an agent can place it in the workflow without opening the 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?

Gives an explicit precondition ('State the price from estimate_credits and get the user's confirmation before calling') and the follow-up action ('poll get_generation for results'), naming both alternative tools and when they apply.

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