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

With no annotations, the description carries the burden well: it discloses that prices are charter seat prices denominated in PLN, that results are destination-level only (no per-flight times), and that TUI is the sole source. It omits any mention of rate limits, caching behavior beyond the schema's no_cache param, or failure modes.

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 tight sentences: the first front-loads what it returns and how to filter, the second qualifies the pricing and its limitation, and the third enumerates shape. No preamble or filler.

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 6 optional params, full schema coverage, and the presence of an output schema, the description is largely complete: currency, price semantics, and the absence of flight times are all covered. Its only redundancy is restating the full result shape, which the output schema already provides, and it says nothing about caching behavior beyond the flag.

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 already 100%, so the 3 baseline is met by structure alone. The description adds meaning on top: the duration window is characterized as a stay length, and the origin/destination airport filters are tied to charter pricing semantics (per-person vs total), which clarifies how adults interacts with the returned prices.

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 the specific resource and scope: charter destinations sold on TUI.pl, filtered by origin/destination airports and stay length, with per-person and total prices. The TUI.pl qualifier implicitly distinguishes it from the itaka_ and rainbow_ siblings, though no sibling is named directly.

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?

It gives clear context for use — stay-length window, airport filters, charter seat pricing — and explicitly excludes a use case: 'There are no per-flight times here; TUI only publishes a destination price,' which routes an agent needing flight-level detail elsewhere. No explicit when/when-not or named alternative is given, so it falls short of a 5.

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