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

With no annotations, the description carries the full burden and does well: it discloses that data comes live from Wizzair's private booking API and is unofficial, so it may briefly fail if Wizzair rotates or throttles it — a real reliability caveat an agent needs. It omits result-size/rate-limit behavior and does not restate the caching behavior (left to the schema's no_cache).

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 tight sentences with zero filler: the purpose and speed advantage come first, the data-source caveat second. Every clause earns its place.

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 five parameters, no annotations, and no output schema, the description covers purpose, intended workflow position, and reliability risk. It stops short of hinting at the response shape (a list of dates), which would have closed the remaining gap, but overall it is sufficient to invoke the tool correctly.

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 five parameters (including no_cache and the date patterns) are already documented in the schema. The description reinforces the route + from/to window shape but adds no format or syntax detail beyond it — 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 concrete resource — the dates on which a route has available Wizzair flights within a from/to window — with enough specificity to distinguish it from the fare-search sibling ('before asking for prices'). The verb is implicit (a list/discovery operation) rather than named, which keeps it just below 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 fastest way to see which days a route operates before asking for prices' gives clear sequencing: use this for date discovery, then move to pricing. It does not explicitly name wizzair_search_fares or wizzair_search_timetable as the alternatives, so the routing is inferred rather than stated.

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