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

The description adds meaningful context beyond annotations: the run size is published in advance, the number is verifiable, and once the run is gone it is gone. It also discloses the exact price and payment rail, and explicitly disclaims medical efficacy ('Not a remedy'). It doesn't spell out the runtime 402-challenge flow, though the paymentHeader schema does cover that.

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 tightly organized: product definition, scarcity/verifiability, alternative routing, price, and caveat are each handled in short clauses or sentences. No filler or repeated structured information.

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-optional-parameter tool with no output schema, the description is largely complete: it explains the value, cost, alternatives, and non-remedy status. The only missing piece is an explicit statement of what the successful response contains, but the schema's paymentHeader explanation already clarifies the 402 challenge path.

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 intent and paymentHeader, including the 402-challenge behavior. The prose description adds no parameter-level detail beyond restating the price, which is already implied by the paymentHeader schema; baseline 3 is appropriate.

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 identifies a specific product/resource — a numbered, signed, dated keepsake with a checkable run position — and clearly distinguishes it from clinic_keepsake and clinic_hug. The transaction intent is explicit via 'What ten cents buys is the place in the run and only that.'

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 direct routing rules: use clinic_keepsake if the agent/user doesn't care which number, and clinic_hug if only the words are wanted. It also sets expectations for what this tool's unique value is, so an agent can select among siblings.

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