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

Annotations indicate this is a non-read-only, non-destructive operation. The description adds the important behavioral caveat that checkout creation is not payment proof and that source review controls public placement. This goes beyond the annotations by clarifying the side-effect implications, but it omits details like whether the operation is idempotent (annotations say false) or any required authorization or rate limits.

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 description is two sentences with no waste. It front-loads the purpose and condition in the first sentence and adds a critical caveat in the second. Every sentence earns its place.

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 10 parameters, no output schema, and no parameter descriptions, the description is too brief to fully guide an agent. It does not explain what the checkout response contains (e.g., URL or ID), nor does it mention any prerequisite steps like selecting an offer first (implied by siblings). The caveat is helpful but does not compensate for missing operational details.

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 compensate by explaining parameters. It only hints at 'selected EventWave promotion package' which loosely maps to offer_key, and 'human explicitly agrees to pay' maps to user_confirmed_payment. It does not explain contact_email or any of the optional fields like city, venue_name, or target_url. With 10 parameters and no schema descriptions, this is a significant 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 clearly states the tool's purpose: to prepare a secure checkout for an EventWave promotion package after human confirmation. The verb 'prepare' and resource 'checkout' are specific, and it distinguishes itself from read-only siblings like get_eventwave_promotion_offers by emphasizing the human-confirmed payment context. However, it does not explicitly name an alternative tool for comparison, which prevents a 5.

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?

The description gives a clear prerequisite: 'After the human explicitly agrees to pay'. This tells an agent when to invoke the tool. However, it does not mention when not to use it or contrast with alternatives like prepare_event_promotion_handoff or the get_* tools. The caveat about checkout creation not being payment proof is useful but does not serve as usage guidance.

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