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

Annotations are already strong (readOnly, idempotent, non-destructive), and the description adds significant behavioral detail: cache behavior, 'cached_for_date' vs 'list_from' pricing, the 'nearest departure' fallback, the per-date price rule, and the complete departure-date calendar. This gives an agent accurate expectations beyond what annotations convey.

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 dense but every sentence earns its place: scope, matching, pricing semantics, date-calendar authority, availability caveat, and cache/no-live-call nature. It is front-loaded with the core purpose and progressively layers the caveats an agent needs to avoid errors.

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 tool with no output schema, the description covers all critical operational details: what data is returned, how to identify the tour, how pricing behaves for specific dates, what not to do with dates, and where live pricing/availability live outside this tool. It is sufficient for correct invocation and response reasoning.

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%, but the description enriches several parameters: 'tour' matching semantics with examples, exact 'tour_id' from tours_list, and how 'date' plus party affects pricing ('cached_for_date' exact total vs 'list_from' nearest departure). It also explains a critical constraint: every departure date has its own price, adding real semantic value beyond the schema.

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 names a clear resource ('ONE organized group tour') and enumerates the exact content returned: departure-date calendar, day-by-day program, duration, transport, price. It also distinguishes itself from sibling categories by emphasizing 'organized group tour' and 'Cache/DB read, no live call', so an agent can tell it apart from list-like or charter tools.

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 gives practical invocation guidance: match by 'tour' fragment or exact 'tour_id' from tours_list, pass 'date' and party when available, and use 'tour_page' for live pricing of any date. It also states exclusions, such as 'Seats/availability are confirmed by staff', which prevents misuse. It does not explicitly enumerate every sibling alternative, but the context and exclusions are clear enough.

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