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

Annotations already cover read-only, idempotent, and non-destructive behavior, so the description adds value by revealing return structure (ranked list, persona-fit score, booking deep-link), persona/personality matching, and the empty-list edge case. However, mentioning 'requested currency' is slightly ambiguous because no currency parameter appears in the schema, though this is a minor gap.

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?

The description is three sentences, with the first sentence front-loading the tool's purpose and output contents, the second giving the usage cue, and the third naming alternatives and the empty-list result. Every sentence earns its place with 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?

Even without an output schema, the description enumerates returned fields and edge-case behavior, and it provides cross-references to sibling tools. It is nearly complete, though the 'requested currency' reference and the undefined 'persona-fit score' leave small gaps in an otherwise strong description.

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?

The input schema already provides 100% coverage with descriptions for all five parameters, so the baseline is 3. The description adds general context about categories and persona matching, but it does not add meaningful parameter-level semantics beyond what the schema already documents.

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+resource: 'Searches bookable tours, activities and local experiences in a destination and returns a ranked list...'. It clearly distinguishes from sibling tools by stating 'For a place to stay use departi_search_accommodation; to get there use departi_search_transport' and gives a concise use-case phrase: 'what can I do in X'.

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 description explicitly states when to use this tool ('Use for "what can I do in X"') and names alternative tools for related needs ('For a place to stay use departi_search_accommodation; to get there use departi_search_transport'). It also sets expectations by noting an empty list is returned if nothing matches.

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