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

Annotations already cover the safety profile (readOnly, idempotent, open world), so the bar is lower. The description adds genuinely non-redundant behavioral context: this is a paid call costing 0.04 USDC via x402 or 20 credits of a Factline API key, which an agent must know before invoking. It does not mention rate limits, latency, or failure modes, so it stops short of a 5.

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 purpose and audience, then a dense but useful enumeration of report contents, closing with input format and pricing. The long content list is information-bearing rather than filler, though the single run-on enumeration could be trimmed slightly.

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 carries the burden of describing what comes back, and it does so comprehensively via the data-domain list. It also discloses input format, target users, and payment mechanics, leaving nothing an agent needs to decide or call correctly.

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 five parameters including the 'q' free-text alternative, addition, house_letter and house_number. The description only states 'Input: postcode + huisnummer', which actually understates the schema's flexibility; baseline 3 is appropriate.

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+resource: a Dutch property due-diligence report for one address, and enumerates the data domains it contains (year built, energy label, WOZ, crime, noise, air quality, amenities). This clearly differentiates it from narrower siblings like nl_home_basic and nl_home_compare.

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 names target audiences (real estate, relocation, mortgage agents) and local-language aliases (woningrapport, huis check), which implies usage. However it never states when to prefer this over nl_home_basic, nl_home_compare, nl_neighbourhood or the single-domain tools, and gives no exclusions or prerequisites.

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