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

Annotations already declare readOnlyHint=true, destructiveHint=false, and openWorldHint=false; the description is consistent with all of these ("our own" matches the closed-world hint). It adds value beyond the annotations by disclosing the return shape ("Returns excerpts and links"), though it says nothing about result limits, ranking, or latency.

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?

One dense sentence front-loads the core action and scope, the topic list is compact and high-signal, and the return-value clause is a short separate sentence. No filler or restatement of the name.

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 usefully compensates by stating the return format (excerpts and links), and the single-parameter surface is fully covered by the schema. Only minor gaps remain around result volume/limits and ranking behavior.

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% and the single parameter already documents itself as "The traveller's question, any language." The description adds no syntax, length, or phrasing guidance beyond that (e.g., the 3–300 character bound is only in the schema), so the 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) and resource (our own Thailand travel guides) with explicit scope, then enumerates the covered content types: transport, last boats, weather/monsoon, Maya Bay rules, island durations, budgets, safety. This clearly separates it from siblings like search_experiences, search_hotels, and search_flights, which cover bookable inventory rather than editorial guides.

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 topic enumeration implies what kinds of questions belong here (practical/logistical guide questions), but there is no explicit when-to-use or when-not-to-use statement and no routing to alternatives such as search_experiences for bookable activities. An agent can infer the fit but gets no stated boundary.

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