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

Annotations declare readOnlyHint and idempotentHint, but the description adds meaningful traits beyond these: the result is delayed, the mint is server-selected (not user-specified), and it explicitly is not a check on the user's mint. This gives the agent accurate expectations about behavior and limitations that structured annotations do not cover.

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 sentences with zero fluff. The key facts – free, exact paid shape, server-picked, not a check – are front-loaded and each carries information. This is a model of concise tool documentation.

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 zero-parameter tool with no output schema, the description is complete. It explains the shape of the return value by referencing the paid mint_risk_card, the selection criteria (aged >= 300s, >= 3 buys, delayed), and the limitation that it is not user-specific. An agent has everything needed to call it correctly.

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?

There are zero parameters, and the schema coverage is 100% (empty object). The description's 'No arguments' reinforces this. Per the calibration baseline for 0 params, this is a 4 – the description adds no new param semantics because there are none to add.

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 what the tool does: it provides a free sample of a full risk card in the exact same shape as the paid mint_risk_card. It explicitly references the paid sibling, making differentiation easy. The phrase 'Use it to see every field before paying' nails the intended purpose without ambiguity.

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 says when to use it ('before paying') and when not to ('the server picks the mint, so it is not a check on yours'). It implies that for a check on a specific mint, the user should use the paid mint_risk_card. This is strong guidance, though it stops short of naming the alternative explicitly.

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