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

Annotations already declare readOnlyHint=true and openWorldHint=true, and the description adds context beyond that: results include stable listing IDs for follow-up calls, and the note that availability is checked per night (so a month-long request demands 30 free nights). These are behavioral insights not captured in annotations. It does not describe pagination or result limits, but the output schema likely covers return shape. Given the strong annotation coverage, a 4 is appropriate.

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?

Four concise sentences with no filler. The purpose is front-loaded, followed by usage guidance and a pointer to follow-up tools. Every sentence earns its place and the description is appropriately sized for a tool with 19 parameters.

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 complex search tool with many parameters, the description covers the essential context: what it searches, how to structure input, what not to do, and what the output provides (stable IDs for subsequent calls). The output schema presumably documents the return structure, so nothing critical is missing. The guidance on dates and the monthly-availability edge case is especially helpful.

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 each parameter is already documented. The description adds meta-guidance: to prefer structured fields over free-text query, and to avoid inventing criteria. It also reinforces the special rule about dates (only use exact dates when the guest gave them). This adds value beyond the schema without repeating it, so a 4 is justified.

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 available vacation rentals across Greece'), and explicitly names the sibling tools for follow-up (get_listing_details, check_availability_and_price), making its role distinct. It leaves no ambiguity about what the tool does and how it differs from related tools.

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 gives explicit operational guidance: use structured fields for concrete criteria, reserve query for unstructured preferences, and never invent data the guest didn't provide. It also names the follow-up tools, effectively telling the agent when to move on after searching. This is clear when-to-use and when-not-to-use guidance.

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