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

Annotations already provide readOnlyHint, idempotentHint, and destructiveHint, and the description adds valuable behavior beyond that: it is cached/validated data with no live call, the price is INDICATIVE and must never be presented as a bookable quote, and the exact price is computed live on the package page. No contradiction with 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?

The description is compact and front-loaded with scope ('NON-charter holiday packages from Tirana'), then moves through destinations, dates, pricing caveat, charter routing, and cached nature. The destination list is slightly long but serves disambiguation. Every sentence contributes, so only minor verbosity keeps it from a 5.

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, cached listing tool with no output schema, the description fully conveys what will be returned: on-sale destinations, validated departure dates, indicative price, and booking link. It also communicates the critical price caveat and the no-live-call behavior. Combined with annotations and full schema coverage, an agent has what it needs to invoke and interpret this tool correctly.

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 covers all parameters with descriptions (100% coverage), including the YYYY-MM-DD pattern for date_to. The description reinforces 'departure dates' and 'validated upcoming departures,' but it does not add new parameter syntax or semantics beyond what the schema already provides. This was the correct baseline.

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 clearly states the verb+resource: it lists NON-charter holiday packages from Tirana (flight+hotel or bus+hotel), including on-sale destinations, validated departure dates, indicative price, and booking link. The word NON-charter and the explicit charter_* mention distinguish it from its main sibling group, making the purpose unambiguous.

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 redirects: 'For Turkey/Egypt beach charters (Antalya, Bodrum…) use the charter_* tools instead.' It also frames the scope as NON-charter packages, and the cached/no-live-call statement sets expectations for when it is appropriate. The primary alternative tool group is named directly, so an agent can route correctly.

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