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

Annotations already cover safety (readOnly, idempotent, openWorld, non-destructive), but the description goes far beyond: it discloses the 0.03 USDC payment requirement, the x402 two-step challenge/sign flow, the 10-minute cache, the live data sources (Base RPC + Blockscout + OFAC index), and that the server never holds a wallet. These are exactly the traits an agent needs and none are duplicated from structured fields.

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?

Front-loaded with purpose, then capabilities, then payment mechanics — logically ordered. It loses a point for repetition: pricing ('$0.03 USDC on Base') and the x402/self-pay point appear two to three times, which is redundant even if partly clarifying.

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, the description carries the return-value burden and does so fully by enumerating the returned fields plus the additive alias names. Combined with the payment flow and caching details, an agent has everything needed to call and interpret it.

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 both address and payment_header are already documented in the schema, including the nested {name, value} shape. The description reinforces the payment_header pattern but adds little syntax or format detail beyond what the schema provides; a 3 baseline 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?

States a specific verb ('Profiles') and resource ('Base wallet/contract address') and enumerates exactly what is returned: is-contract, activity timestamps, tx counts, balances, counterparties, label hits, OFAC check, risk summary. An agent can distinguish it from wallet_profile_preview and the many signal_/bundle_ siblings without opening any schema.

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?

Clearly explains the invocation pattern: 'Call with no payment_header first to receive the payment requirements; your own wallet pays, never this server's.' This is strong operational context. It stops short of explicitly contrasting with the free wallet_profile_preview sibling or stating when the paid version is warranted over it, so not a 5.

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