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

Annotations already declare this a safe read-only, idempotent, non-destructive call, and the description adds substantial context on top: the single-niche constraint, the mandatory cohort scoping, and a full enumeration of return fields. With no output schema present, this disclosure of what comes back is doing real work rather than restating annotations.

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-loaded with the purpose and the 'Call this FIRST' directive, then organized into parameters and returns. The returns list is long, but with no output schema it substitutes for one and each field earns its place; slight verbosity is the only deduction.

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?

Given four required parameters, no output schema, and no schema descriptions, the definition supplies parameter meanings, the group-size scoping rationale, the complete return shape, and prescriptive guidance for using byMonth, topDestinations, and averages. Nothing an agent needs to call this correctly 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?

Schema description coverage is 0%, so the description carries the full burden and does: it enumerates the niche values, the lone market code, and the 1-20 / 0-20 bounds. More importantly it explains the semantics behind the required occupancy parameters — 'counts and prices depend on group size — the overview is scoped to this exact cohort' — which is meaning the schema cannot express.

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 ('Get a comprehensive overview of the available travel data') and pins the scope to exactly one niche. The instruction 'Call this FIRST' plus 'before searching' clearly positions it ahead of siblings find_trips, get_facets, and search_listings, so an agent can pick it without opening a 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?

Strong ordering guidance ('Call this FIRST') and an explicit multi-call rule for comparing niches ('call once per niche'). It does not name the sibling tools or state when this overview is unnecessary, but the sequencing guidance is unambiguous enough to route correctly.

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