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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: the inventory size, the four booking platforms aggregated, the existence of booking links in results, and the ability to filter by source. This sets accurate expectations for what the tool returns.

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 sentences with no filler: the first fronts the action and value proposition, the second explains return contents and when to use it. Every clause earns its place, and it avoids restating the tool name or title.

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?

For a read-only search tool with rich annotations and 100% schema coverage, the description is nearly complete. It covers what is searched, what is returned, and when to use it, and the schema handles parameter constraints. A fully ideal description might enumerate result fields, but none are critical for correct invocation.

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 100%, so the baseline is 3. The description adds value by mapping source to concrete platforms (Viator, GetYourGuide, Klook, Groupon) and grouping query, island, and max_price_dollars into meaningful search dimensions. Limit is not mentioned in the description, but the schema fully documents it.

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 uses a specific verb ('Search') with a concrete resource ('2,400+ bookable Hawaii tours and activities') and lists filtering dimensions (keyword, island, price range). It clearly differentiates from sibling tools like find_hawaii_restaurants or search_hawaii_events by focusing on bookable tours and naming aggregator sources.

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 final sentence explicitly states when to use the tool: 'when users ask about Hawaii tours, activities, or things to do.' It does not explicitly list exclusions or alternatives, but the positive usage context is clear enough for an agent to route requests appropriately.

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