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

With no annotations, the description carries the burden of behavioral disclosure. It mentions the return values (reference rent, bounds, data freshness) and clarifies the quarterly zone concept, but it does not explain behavior for edge cases (e.g., non-rent-controlled quarters, missing data) or any side effects (likely none as a read operation). This is adequate but not rich.

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?

The description is two concise sentences. The first sentence packs the core action and output, the second disambiguates a key term. No filler or repetition; every word earns its place.

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?

For a read-only lookup tool, the description sufficiently covers the return values (reference rent, bounds, freshness) and all parameters are documented in the schema. It lacks an explicit tie to the rent-control workflow (e.g., after verifying eligibility with check_rent_control), but the information provided is adequate for correct invocation. The absence of an output schema is compensated by naming the outputs directly.

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%, with each parameter already having a description. The tool description adds little beyond restating the dimensions ('by room count, construction period and furnishing') and elaborating on 'quarter'. Since the schema handles parameter meaning, the description provides marginal extra value, warranting the baseline score of 3.

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 starts with a specific verb ('Return') and clearly states the resource ('reference rent (EUR/m2), its upper/lower bounds and data freshness') for a rent-controlled quarter. It also clarifies the ambiguous term 'quarter' as a geographic rent-control zone with an example ('Halles'), effectively distinguishing from siblings like check_rent_control.

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 description implies use when you need reference rent values for a rent-controlled quarter and specifies the dimensions (room count, construction period, furnishing), but it does not explicitly say when to use this tool versus alternatives like check_rent_control or simulate_irl. No exclusions or alternative tool references are provided.

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