search_rentals

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

Annotations already declare read-only, idempotent and open-world, so the description is free to add real value — and it does: results are de-duplicated across three live sources, facts are pre-extracted (price in EUR, rooms, surface, heating, parking), and per-site status is returned, implying partial-source failures are visible. It does not mention latency or rate-limit behavior beyond the schema's 'more = slower' note.

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 sentences, zero filler, front-loaded with source and scope before the return contract. Each clause carries distinct information (sources, de-duplication, extracted fields, links, per-site status).

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 14-parameter read tool with no output schema, the description does the important work of characterizing what comes back (de-duplicated records with extracted facts and source links, plus per-site status). What remains unstated is how partial site failures surface and how limit interacts with per-site paging, though the schema covers the latter.

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%, so every one of the 14 parameters is already documented, including non-obvious ones like owner_only's site-coverage caveat and parking statuses. The description adds nothing parameter-specific beyond confirming that prices are in EUR and that parking/heating are extracted facts; 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?

States a specific verb+resource (search apartments for rent) with an explicit geographic scope (a Romanian locality) and named sources (storia.ro, publi24.ro, lajumate.ro), plus the return shape. It does not name any sibling, so the distinction from get_listing_details or search_parking must be inferred from the nouns alone.

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?

Usage is only implied: the description tells you what it returns, which signals 'use this for discovery, then get_listing_details for a full ad', but never says so or states exclusions. No prerequisites or when-not-to-use guidance is given, leaving the agent to infer the workflow from sibling names.

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