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

Goes well beyond the readOnly/idempotent/openWorld annotations by disclosing that the check is deterministic, backed by a local curated blocklist, incomplete in coverage, and non-authoritative on a negative result. These are exactly the behavioral traits an agent needs before relying on the output.

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?

Three sentences, front-loaded with the core action, then scope exclusions, then the caveat. No filler, and the most decisive information leads.

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?

An output schema exists, so return values need no explanation, and the description fully covers scope, determinism, coverage limits, and the non-clearance caveat. Nothing an agent needs to call and interpret this tool 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?

Schema coverage is 100% and the single 'subject' parameter is already documented as an EVM address or ISO country code/jurisdiction name. The description reinforces the accepted input types but adds no syntax, formatting, or edge-case 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: deterministic screening of EVM addresses and jurisdictions against a curated local blocklist. It explicitly scopes itself to address- and jurisdiction-level checks and rules out name-based screening, letting an agent distinguish it from siblings like iban_check or swift_bic_check.

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 clear when-not guidance ('NOT name-based screening and NOT a complete OFAC SDN check') and a strong caveat that absence of a match is not clearance, directing use as one informational compliance input. It stops short of pointing to an alternative tool when a full name-based SDN check is actually needed.

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