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

Annotations already declare readOnly, idempotent, openWorld, non-destructive, so safety is covered. The description adds genuinely useful behavior beyond that: the provider chain (GetYourGuide primary, Viator and Tiqets fallbacks) and the return shape. It omits rate limits and does not explain why 'tiqets' appears in the fallback text but not in the provider enum.

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 tight sentences, front-loaded with purpose then return shape then usage then constraint. Minor redundancy between the resource list in sentence one and the 'things to do, tours, activities' list in sentence three, but nothing is wasted.

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 correctly fills the gap by enumerating the returned fields (titles, prices, ratings, durations, booking links). Combined with the usage trigger and per-call destination rule, an agent has everything needed to invoke it 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 six parameters (including currency fallback chain and trip_id defaults) are already fully documented in the schema. The description's 'Search one destination per call' merely restates what the query parameter description already says, adding no new parameter meaning. 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 specific verb (Search) plus resource (bookable tours, activities, excursions, experiences) and names the primary source (GetYourGuide) with fallbacks. This clearly distinguishes it from siblings like search_attractions, search_hotels, and search_flight_prices.

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?

Explicit trigger conditions are given: 'Use when the user asks about things to do, tours, activities, excursions, or experiences in a city or destination.' The 'one destination per call' constraint is a useful operational rule. However, it never names the closest alternative (search_attractions) or says when to prefer one over the other.

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