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

Annotations already cover the safety profile (readOnlyHint, idempotentHint, openWorldHint, destructiveHint=false). The description adds genuinely new behavioral context the annotations cannot: it reads several live calendars and therefore can take a few seconds, plus the 31-day date-range ceiling and the 1-to-5 result cap.

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?

Three sentences, front-loaded with purpose, then required inputs, then result shape and the latency caveat. Every sentence carries distinct information with no filler or repetition.

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?

An output schema exists, so return values need not be spelled out, yet the description still summarizes the response (cards plus up to three open start times and the original tour's status), which is a slight redundancy but harmless. Combined with the latency note and range limits, nothing essential for correct invocation is missing.

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?

With only 50% schema description coverage, the description compensates by explaining the key inputs: bokun_id is the traveler's desired tour, the date/range is capped at 31 days, and party_size or travelers (with party_size winning) define the group. It adds meaning beyond the raw schema properties, though it does not restate the full traveler age breakdown.

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 and resource with scope: find tours similar to one given tour that have open start times on a date or date range. This is clearly distinguishable from siblings like search_tours (general discovery), check_availability (single-tour status), and compare_tours (comparison), so an agent can route correctly without opening any schema.

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?

Gives concrete usage context: 'Pass the tour the traveler wanted (bokun_id), the date, and party_size or travelers', making it clear this is the fallback when a specific tour lacks open start times. It stops short of explicitly naming when to prefer it over check_availability or search_tours, so it is clear but not fully routed.

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