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

Annotations already declare readOnlyHint, idempotentHint and destructiveHint=false, so safety is covered. The description adds genuinely useful behavior beyond that: prices are 'from' prices with a basis rather than fixed prices, and a no-match query returns an empty list plus an emptyReason instead of an error.

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 that front-load the core capability, then the price caveat, then the empty-result behavior and scope boundary. No filler or redundancy.

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 an output schema present the return shape need not be described, yet the description still flags emptyReason, and it covers price semantics and catalogue scope. Only pagination/sort-default behavior is left entirely to the schema, which is a minor omission for an 11-parameter search tool.

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 coverage is 91%, so the schema documents nearly every parameter including enum values, defaults and the minor-units convention for maxPrice. The description mostly restates the filter fields; its only semantic addition is the 'from-price with basis' caveat that helps interpret maxPrice.

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 pair (lists/filters) plus an exact resource (published tours) and enumerates the filter dimensions. The closing clause 'Tours only: no hotels, experiences or visas' actively separates it from siblings like list_hotels and search_transfers.

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 'Tours only' line draws a useful scope boundary against some siblings, and the filter list implies the search use case. However, it never says when to prefer this over compare_tours, find_last_minute_tours or get_tour, and gives no prerequisites or exclusions for those alternatives.

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