Screen a blockchain address for AML risk (free)

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

Annotations cover safety (readOnly, idempotent, openWorld), yet the description adds substantial context beyond them: what data sources are checked (OFAC, mixers, scam lists, issuer freezes, on-chain heuristics), the three verdict values, a 0-100 score and blocked flag, the important caveat that 'clear' is not a safety guarantee, and chain-dependent screening depth. It also discloses no auth or cost barrier.

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?

It is a dense block rather than short sentences, but it is front-loaded with the action and trigger, and nearly every clause carries distinct information. The trailing 'Free, no API key, no signup' slightly duplicates the title and cost framing already stated, a minor redundancy.

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 must describe the return payload, and it does precisely: verdict enum, 0-100 risk score, blocked flag, and clickable evidence. It also flags the critical interpretive limit of a clear verdict and points to an external coverage document for chain depth.

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 address formats, lang, and the network enum (including auto-detection behavior). The description restates the supported address families (EVM, Tron, Solana) but adds no new format or syntax detail, 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?

States a specific verb and resource — 'Run an AML compliance screen on a single blockchain address' — and the word 'single' implicitly separates it from the sibling batch_screen. An agent knows exactly what this tool does and at what granularity without opening the 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?

Gives a clear trigger condition ('BEFORE paying or receiving from it') that tells the agent when in the workflow to call it. It does not explicitly name batch_screen as the alternative for multiple addresses, but the 'single address' scoping makes the division of labor inferable.

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