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

Annotations already declare readOnly, idempotent, closed-world and non-destructive, so safety is covered. The description adds genuine behavioral context beyond that: results are unopinionated (no scoring or ranking), each figure carries its period and comparison baseline, and source attribution is included. It says nothing about caching, rate limits, or what happens when a place name is ambiguous.

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 resource and output shape, then input routing, then the neutrality caveat — a sensible order with little padding. The parenthetical category list plus 'and more' is slightly loose but earns its place by signalling breadth.

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, so the description carries the return-value burden and does it well: headline figures, per-category figures, periods, comparison areas, and attribution. Remaining gaps are minor — no note on error behavior for unknown places or on how many figures to expect per category.

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?

With only 60% schema description coverage, the description compensates meaningfully by explaining the two input modes (a bare place name versus a type + slug pair sourced from resolve_place), which the schema alone leaves implicit for the undocumented slug/type properties. It does not explain the interaction or precedence when both place and slug/type are supplied.

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 (neutral CBS figures for a Dutch municipality, district or neighbourhood), names the exact figure families returned, and clarifies it does not score or rank areas. An agent can distinguish it from get_property or search_listings 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?

Gives concrete input routing: 'Pass a place name, or type and slug from resolve_place', which explicitly ties it to the resolve_place sibling. It does not state exclusions (e.g. when a property-level tool would be better), so it stops short of full when-not guidance.

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