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

Annotations already declare readOnly/idempotent/openWorld=false, so safety is covered. The description adds real context: fromPriceUsd covers the smallest party, priceUnit disambiguates per-person vs per-party, up to 12 rows returned, hotel pickup included, and duration excludes transfer time – all disclosed caveats that prevent misreading the data.

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?

Front-loads scope and offering examples, then bundles the pricing and duration caveats efficiently. Dense but nearly every clause conveys a usable fact; the parenthetical tour list is the only slightly expendable part.

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 carries the burden of explaining return fields (fromPriceUsd, priceUnit, duration) and does so adequately. Minor gap: it doesn't describe the shape of returned rows beyond pricing and duration, though for a list tool this is close to complete.

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% with both 'area' and 'query' already documented with examples, so the baseline is 3. The description only says 'Optional keyword or area filter' without adding syntax, matching behavior, or precedence beyond what the schema provides.

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 (list), resource (private tours and day packages), operator and geography, plus concrete example offerings. It clearly separates itself from get_tour by scoping this as the browse/list entry point rather than the detail lookup.

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?

Explicitly routes the agent: 'Use get_tour with guests for the exact total' for precise pricing, while this tool returns fromPriceUsd. It also states the filters are optional and the row cap, so an agent knows what to expect without trial-and-error.

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