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

Annotations already cover safety (readOnly, idempotent, openWorld), and the description adds substantive context beyond them: fuzzy matching behavior, the default 5-year recency window for former PEPs, and the full payment model (0.005 USDC via x402, 3 API credits, first 5 paid calls free). For a paid tool, the pricing disclosure is exactly the kind of pre-call information an agent needs.

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-loads the trigger clause, then scope, then matching behavior, then cost. No sentence is filler; even the pricing and free-tier details earn their place because they change whether an agent should call this tool.

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?

No output schema exists, and the description does not say what a result looks like (match/no-match, confidence, matched positions or dates), which is a real gap for a screening tool where the agent must interpret the response. Everything else an agent needs to decide and invoke correctly is present.

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% with examples for name, country and birth_year, so the schema carries the documentation burden. The description adds one useful hint — 'fuzzy matching with positions, country and dates' — but does not explain how country or birth_year influence matching. 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 and resource ('check whether a person is a politically exposed person') and then enumerates the exact PEP categories and country scope covered, which no sibling name conveys. An agent can tell this apart from eu_sanctions_screen, pep_batch and kyc_check without opening any 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?

Leads with an explicit trigger ('Use when you must check whether a person is a PEP for AML/KYC') and notes it pairs with sanctions screening, giving clear context. It never names the closest sibling (pep_batch) or states a when-not condition, so it stops short of full routing guidance.

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