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

Annotations already flag this as non-read-only and non-idempotent; the description adds valuable context: the $19 price, the required human confirmation, and the warning that creating a checkout is not proof of payment. No contradiction with the 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?

Two purposeful sentences with the precondition front-loaded and no filler. Every clause carries operational meaning.

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 two-parameter tool with annotations covering the write/side-effect profile, the description is nearly sufficient: it gives the precondition, price, secure context, and a key caveat about payment proof. The return shape is unspecified, but with no output schema the invocation path is still clear.

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. It does interpret user_confirmed_payment as the human's explicit agreement to pay $19, but it adds nothing about the email parameter beyond what the schema's format and pattern already state. Partial compensation for a simple two-parameter tool.

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 ('prepare') and resource ('secure Evercraft Payments checkout') with a clear precondition. It is readily distinguishable from the sibling get*/run actions even without naming them.

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 a precise when-to-use condition: only after the human explicitly agrees to pay $19 for the 7-day Interview Sprint. It does not explicitly route away from sibling tools, but the precondition and the 'not payment proof' caveat provide clear usage context.

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