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

Annotations cover safety (readOnly, idempotent, openWorld), and the description adds real value on top: the authoritative data source, exactly what is returned (existence, exact spelling, WGS84 coords, BAG ids, municipality, province, CBS code), and the cost/auth model (0.002 USDC via x402 or 1 Factline credit). Error/not-found behavior remains unstated.

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 operation and its inputs, then outputs, then use cases, then pricing. Every sentence carries distinct information (what, what-you-get, who-for, source, cost) with no 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?

With no output schema and no annotations on cost, the description correctly compensates by enumerating return fields and pricing. Given five optional params and no required ones, what is missing is only the negative case (address not found) and its relation to the batch/reverse siblings.

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 already 100%, so the baseline is 3, and the description usefully explains the two input modes — structured postcode + house number versus free-text — which is the key decision an agent must make among these five optional parameters.

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 pair (verify/geocode) and a specific resource (Dutch address, postcode + huisnummer), and names the underlying register (BAG/Kadaster via PDOK). It does not, however, distinguish itself from close siblings like nl_address_batch or nl_address_reverse, which an agent would plausibly confuse it with.

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?

It lists target scenarios (KYC, onboarding, delivery, CRM cleanup, real estate agents), which implies when to reach for it, but gives no explicit when-not and no routing to the batch or reverse siblings. Usage context is present but alternatives are left to inference.

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