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

Annotations already cover the safety profile (readOnly, non-destructive, idempotent, closed-world), so the bar is lower. The description adds genuinely useful context beyond them: the supported geographic granularity (municipality/Kreis/Quartier) and the shape of each returned record (year, area level, source).

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?

A single front-loaded sentence that opens with the usage cue and then lists metrics. The multilingual parenthetical is dense but it is the tool's real vocabulary surface, so it earns its place; still, the trilingual metric list is heavier than strictly needed.

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?

There is no output schema, and the description compensates by enumerating the returned fields (prices per m², rents, land prices, vacancy rate, each with year, area level and source). Combined with annotations covering safety, an agent has enough to call this correctly; only the boundary with property-value siblings is left open.

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 100%, so both parameters are already documented, giving a baseline of 3. The description reinforces the `place` semantics by naming the area levels (municipality, Kreis, Quartier) and demonstrates multilingual support that maps to the `language` enum, but adds no format or constraint detail beyond the schema.

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 (market figures for a Swiss municipality, Kreis or Quartier) and enumerates the exact metrics returned: per-m² condo/house prices, rents, land prices, vacancy rate. It implicitly separates itself from property-level siblings like property_value_range by scoping to area-level aggregates, but never names a sibling explicitly.

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?

The 'Use this for...' framing gives a clear trigger condition, but there are no exclusions or alternatives. An agent cannot tell from this text whether an area-level question should go here or to property_value_range/address_facts when the query is ambiguous.

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