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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and non-destructive, so the safety profile is covered. The description adds genuinely new behavioral context beyond the annotations: the two data sources screened, that matching can be fuzzy or exact with configurable similarity, and the pricing model ($0.005/call after 5 free/day), which matters for call budgeting. It stops short of describing what a match result looks like or list-refresh currency, though an output schema exists.

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?

Two sentences, front-loaded with the capability and sources, with pricing isolated in a parenthetical so it can be skipped. Every clause carries information; only the pricing aside is slightly tacked on rather than integrated.

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 not be explained, and the annotations cover the safety and idempotency profile. Combined with the named lists, matching modes, and cost model, an agent has enough to decide to call it and how to tune the threshold, though sibling selection remains slightly underspecified.

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 carries per-parameter meaning and the baseline is 3. The description adds context that the threshold parameter controls fuzzy-vs-exact similarity behavior, but it does not clarify how 'exact' mode interacts with the threshold value or how country and registrationNumber affect matching strictness.

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?

The description states a specific verb and resource ('sanctions screening') and names the exact data sources covered (OFAC SDN, EU Financial Sanctions), plus the matching modes (fuzzy and exact). It does not differentiate against siblings like check_vendor or verify_bank_payee, so an agent cannot tell from the text alone which screening tool applies in a given case.

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?

Usage is only implied: the agent can infer this is the tool for sanctions/compliance checks, and 'exact' vs 'fuzzy' with configurable thresholds hints at when to lower thresholds. There is no explicit when-to-use, no exclusion of the sibling verification tools, and no statement of prerequisites or follow-up steps on a hit.

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