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

With no annotations, the description carries the full load and does well: it names the data provenance (OFAC, ScamSniffer, MEW, eth-labels, curated Base/Tornado sets), defines the sanctioned-vs-flagged distinction against the OFAC SDN list, and states 'never guesses' and 'Free'. It stops short of stating read-only status explicitly, auth requirements, rate limits, or caching, so a top score is not earned.

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 the core distinction, then params and return shape; every clause carries information (enum values, provenance, semantics). It is dense and slightly run-on, with the source list and category list competing for attention, but not padded.

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?

There is no output schema, so the description fully compensates by enumerating the return object ({ address, chain, is_known, label, category }) and spelling out all category values, including the edge-case semantics of 'sanctioned' vs 'flagged' and 'unknown'. For a 2-parameter lookup tool this is complete.

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% and the description only restates the same facts — address format/requiredness and chain default/alternatives. It adds no syntax, normalization, or validation detail beyond the schema, 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+resource ('Entity attribution — what IS this address') and immediately scopes it against the ownership-style siblings with 'not who owns it', which separates it from caller_id and lookup_wallet. An agent can pick this tool 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?

The contrast clause 'what IS this address, not who owns it' effectively routes the agent between this and the identity/ownership tools. There is no explicit when-not or prerequisite statement (e.g., that only EVM addresses on base/ethereum are supported), but the usage context is clear.

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