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

Annotations already declare readOnlyHint, idempotentHint and openWorldHint, so the safety profile is covered. The description adds two useful behavioral facts beyond the schema: the call is free (implying no auth/cost friction) and the data provenance (BAG, CBS, Leefbaarometer), but says nothing about freshness, rate limits or latency.

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?

Three short sentences, front-loaded with the cost signal and then the returned facts. Dense and largely waste-free, though the field list could be tightened into a more scannable form.

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 usefully enumerates the returned fields, which is the right compensating move. However, it never explains the input contract — that either postcode + house_number or the free-text 'q' must be supplied despite zero required parameters — leaving a real ambiguity for the agent.

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 every parameter is self-documented, including the note that 'q' is an alternative to postcode. The description contributes no additional parameter guidance, so the 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?

The description names the resource ('a Dutch address') and enumerates exactly which facts are returned (year built, floor area, use, neighbourhood residents, average home value, Leefbaarometer percentile). An agent can tell it is a single-address lookup distinct from nl_home_compare or nl_home_report, though those siblings are never named.

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?

Only 'Free' hints at when to pick this over the paid siblings; there is no explicit statement such as 'use for a single address snapshot, use nl_home_compare for side-by-side'. No prerequisites or exclusions are given.

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