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

With no annotations, the description carries the full burden and does so well: it discloses the tool is free, requires no arguments, needs no authentication beyond a wallet address, and lays out concrete pricing tiers (0.10 EUR admission plus conditional 2.90/1.45 EUR) and callback events. This is unusually rich behavioral context for a zero-parameter tool.

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?

Purpose is front-loaded in the first clause and the rest is organized into what it returns vs. how to use it. The parenthetical price detail is dense but genuinely informative rather than filler, so it remains tight overall.

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 no output schema or annotations, the description must describe the return surface itself, and it enumerates the service summary, authentication mode, live price terms with asset amounts and exchange rate, callback events, and agent rules. Nothing an agent needs to call this correctly is missing.

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, so the baseline is 4. The description reinforces this by stating it "needs no arguments," leaving no ambiguity about invocation syntax.

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 and resource: it describes the Verifi service, how to pay, and current price terms. It's clearly an informational/discovery tool, and it gestures at the sibling relationship by naming verify_claim as the authoritative source for payment requirements, though it doesn't fully delineate itself from get_verify or unlock_verify.

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?

"Call it once to plan" gives clear timing guidance, and it explicitly redirects to verify_claim for the authoritative payment requirement, which names an alternative and the condition selecting it. It lacks explicit when-not-to-use exclusions, keeping it short of a 5.

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