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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, so the safety profile is covered. The description adds valuable behavioral context beyond annotations: it explicitly states the tool never fabricates a match or clear, instructs the agent to check lists_screened, and explains the reason_code 'partial_screening' behavior when a source fails. This is exactly the kind of non-obvious runtime behavior an agent needs to interpret results correctly.

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?

The description is compact and front-loaded with the core purpose, then adds critical exclusions and behavioral rules. The pricing note is slightly tangential but useful for an agent deciding whether to call. Every sentence earns its place; a small deduction for the pricing aside being somewhat out of place in a tool description.

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?

For a read-only screening tool with no output schema, the description covers the essential behavioral contract: which lists are screened, which are not, how to interpret partial failures, and the no-fabrication rule. It doesn't describe the exact return shape, but the description's guidance on lists_screened and reason_code partially compensates. Given the tool's complexity and the absence of an output schema, this is strong but not perfect.

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 all three parameters. The description adds context about the screening scope and result interpretation, but it doesn't add parameter-specific meaning beyond the schema. Baseline 3 is appropriate when the schema carries the parameter documentation burden.

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 ('screening') and resource ('name/entity against sanctions lists'), and enumerates the exact lists covered (OFAC SDN, EU consolidated, UK FCDO). It also explicitly excludes the UN Consolidated List, which distinguishes it from any generic sanctions-screening sibling and prevents an agent from assuming broader coverage.

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 description gives explicit when-to-use context: free screening of a name/entity against sanctions lists, with a clear exclusion (UN list not screened) and a behavioral rule (never fabricate a match or clear; check lists_screened; reason_code 'partial_screening' if any source failed). It also notes quota/pricing, which helps an agent decide when to call it. While it doesn't name a specific alternative sibling, the exclusions and conditions are strong enough to guide selection.

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