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

Annotations only cover read-only/open-world/idempotent. The description goes well beyond that by disclosing pricing (0.0015 USDC per address, 0.015 total, or 8 credits), the billing edge case that unfound addresses are flagged but not charged extra, and the optional energy-label output. This is exactly the extra behavioral context an agent needs before invoking a paid tool.

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 core purpose and scope, then adds output fields, usage context, and pricing in a compact form. Three sentences with almost no waste; only the lengthy output-field enumeration borders on list-dumping, but it is informative rather than 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, the description compensates by enumerating what is returned, and it discloses cost and the unfound-address billing rule. Combined with annotations covering the safety profile, an agent has everything needed to call this correctly and price it.

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% and both parameters are documented there, so the schema does the heavy lifting. The description mentions 'optionally the registered energy label' which maps to the include parameter but adds no syntax or format detail beyond the schema, so 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 (bulk enrichment) and resource (up to 10 Netherlands addresses per call), and enumerates the returned data categories (BAG address, coordinates, CBS neighbourhood, crime, home value, energy label). The batch scope plus 'up to 10 per call' cleanly distinguishes it from the single-address sibling nl_address_lookup without needing to name it.

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?

Provides clear usage context ('For daily real estate, relocation, CRM and lead-enrichment pipelines'), which tells the agent where this tool fits. It does not, however, state when NOT to use it or explicitly point to nl_address_lookup for single addresses, so it stops short of full when/when-not guidance.

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