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

Beyond the annotations (which only say it is a non-read-only, non-idempotent, open-world write), the description adds critical non-obvious behavior: 'Nothing is charged here,' the link expires in 7 days, the price is computed by the site, and the customer completes checkout in the cart. These directly inform how the agent should present the result.

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 purpose and no-charge fact are front-loaded in the first two sentences, followed by expiry, the confirmation precondition, and pricing. It is dense but every sentence carries information, with only the cart-mechanics clause ('adds photos... pays with PayPal') bordering on detail that could be trimmed.

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 an output schema present, return formatting does not need explanation, and the description covers purpose, safety ('nothing is charged'), lifetime, and preconditions. The 9-parameter surface is largely handled by the schema, so nothing essential to correct invocation appears missing.

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 78%, so the schema already documents most parameters (product, theme, note_count, variation_id, etc.). The description only references 'the song, the variation and the price' and adds no syntax or format detail beyond what the schema provides, so it stays at the high-coverage baseline.

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 precise verb+resource ('Prepares a custom melody or strip design order') and its key side effect (returns a cart link for review and PayPal payment). It clearly distinguishes this order-preparation tool from siblings like create_song, get_order_status, or render_audio.

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?

It gives an explicit precondition: 'Confirm the song, the variation and the price with the person before calling it.' This tells the agent when the call is appropriate, though it never names alternative tools or states when *not* to use it.

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