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

Annotations already declare read-only, non-destructive, idempotent behavior. The description adds useful context beyond that: the search is live, returns total direct-booking price in EUR, and includes a booking link. It does not discuss rate limits, caching, or what happens when no apartments are free.

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?

Two short sentences, front-loaded with the core search purpose and followed by the key return details. There is no redundant or wasted phrasing.

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?

With no output schema, the description should carry return-value burden; it does explain that the result is free apartments, total price, and a booking link. It leaves gaps around result structure and handling of zero availability, but covers the essential return information.

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 all seven parameters are already documented directly in the schema. The description adds only marginal meaning, mainly tying dates and guests to the search and noting EUR pricing, without clarifying enum choices or parameter interactions.

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 states a specific verb and resource: a live search for apartments that are free for given dates and guests, including price and booking link. It implies a multi-apartment search distinct from siblings like get_quote or list_apartments, but does not explicitly name or contrast those alternatives.

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 implied: this is the tool for checking availability and price for a stay. However, it never states when to use it versus get_quote, get_calendar, or list_apartments, nor does it give exclusions or prerequisites beyond the required dates.

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