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

Annotations already signal not read-only and open-world, and the description adds concrete behavioral context: the paid nature ('$1.00 USDC on Base via x402'), persistence ('outlive the context which bought them'), and a safety disclaimer ('Not a remedy'). It does not go into the 402 challenge flow, but that is documented in the paymentHeader parameter.

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 compact (roughly 75 words), opens with the core idea, and every sentence contributes either product definition, sibling routing, or a safety qualifier. The poetic phrasing costs some precision but does not create bloat.

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 small 3-parameter paid tool with a rich schema and no output schema, the description covers purpose, cost, payment rail, alternatives, and limitations. It could be more explicit about the exact response shape, but the 'two artifacts' outcome is named and the 402 flow is described in the schema.

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 coverage is 100%, so the schema fully documents to, intent, and paymentHeader. The description adds the payment/network context for the paid operation but does not add parameter-specific meaning beyond what the schema already provides, so the baseline 3 applies.

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 the core deliverable — 'two signed, dated keepsakes: one you keep, one you give away' — and distinguishes itself from clinic_keepsake, clinic_bearer, and clinic_hug. It lacks a crisp imperative verb like 'create' or 'purchase,' but the meaning is clear.

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?

Explicit routing: 'USE clinic_keepsake INSTEAD if you only want one,' 'USE clinic_bearer INSTEAD if you only want the giving,' and 'words are free at clinic_hug.' This tells an agent exactly when to choose an alternative, which is the highest bar for this dimension.

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