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

There are no annotations, so the description carries the full burden of behavioral disclosure. It only restates filter capabilities that are already present in the schema and gives example queries; it does not mention pagination behavior, output format, whether results are summaries or full listings, default ordering, or any side effects. 'Search' implies a read operation, but no concrete behavioral context is added.

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 three sentences with no filler: it front-loads the action and resource, lists the key filter dimensions, and closes with useful examples. The second sentence partially overlaps with schema property descriptions, but the examples justify the extra length.

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?

Given 19 optional parameters, no annotations, and no output schema, the description provides only a broad orientation and relies heavily on the schema for parameter details. It does not clarify what a bare call returns, pagination defaults, or result object shape, leaving operational gaps. However, the schema's 100% parameter coverage and the examples make the tool usable enough for an agent to attempt a call, so this is adequate with clear gaps rather than deficient.

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 detailed descriptions for all 19 parameters, including units, enums, defaults, and examples for fields like address_city and per_page. The description adds only illustrative city names and natural-language query examples, which do not meaningfully extend the parameter semantics. Baseline 3 is appropriate because the schema does the heavy lifting.

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 opens with a specific verb and resource ('Search Swiss apartments and houses for rent or sale') and then enumerates the main filter dimensions plus three concrete examples. It is clearly about a property search tool, but it does not explicitly set it apart from sibling tools like get_popular_listings or get_similar_listings, so it stops short of a 5.

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 examples imply that this is a general-purpose property search entry point, but there is no explicit statement of when to use search_listings versus alternatives such as get_listing_detail, get_popular_listings, or check_rental_chances. No exclusions or conditions are given, so the guidance is effectively absent beyond the tool's own existence.

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