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

Annotations already cover safety (readOnly, idempotent, non-destructive), but the description adds substantial non-obvious behavior: 10 calls/min rate limit, $0.010 USDC x402 payment with PaymentRequired on unpaid and no charge on failure, forex inclusion tied to include_forex, lists_as_of freshness reporting, and a triage-not-legal disclaimer. Matching semantics (case-insensitive substring, exact >> partial) are also disclosed.

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 capability before caveats, alternatives, and payment mechanics, and almost every clause carries information. It is dense and long for a 2-parameter tool, but no sentence is redundant filler.

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. Given a low-complexity two-param tool, the description covers cost, rate limits, failure charging, matching behavior, optional-parameter effects, freshness metadata, and a disclaimer — nothing an agent needs to call it 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%, so the two parameters are already documented, establishing a baseline of 3. The description goes beyond the schema by explaining the matching algorithm behind 'name' (case-insensitive substrings with exact matches weighing far more, partials only reaching review level) and the country-detection condition governing include_forex.

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?

Names a specific verb (profile) and resource (one person or company) and enumerates the concrete capabilities: watchlist screening, AML country risk, Mauritius registry records, and a composite risk score. It explicitly separates itself from screen_entity and screen_cross_border_payment, so an agent can route without opening a 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?

States when to use it (onboarding KYC/KYB or enhanced due diligence) and names the two alternatives with the exact conditions that select them ('when a list check is enough', 'for both parties of a payment'). This is explicit when/when-not/alternative guidance.

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