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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is covered. The description adds real behavioral detail beyond that: results are filtered to offers valid on valid_on (defaulting to today), and booking_url is only present for partners that have one, which warns the agent the field may be missing.

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 short sentences, front-loaded with what is returned and immediately followed by the validity filter. The final sentence describing booking_url and canonical_url partially duplicates the output schema, keeping it just shy of 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?

With an output schema present, the description needn't enumerate return values, and annotations plus full schema coverage handle safety and parameter detail. The remaining gap is routing guidance against the many destination_* siblings, which the description does not address.

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 100%, so all six parameters (including area/category slugs and cursor pagination) are already documented in the schema. The description restates the valid_on behavior but adds no syntax, format, or interaction detail beyond it, so the baseline 3 applies.

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 ('Find a named destination's current deals and packages') plus the linkage to the partner booking link, which is enough to distinguish it from destination_events or destination_listings by resource type. It does not explicitly name a sibling or contrast scope, so it falls short of a 5.

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 implies the use case (look up current deals for a destination) and notes the validity filter, but never says when to prefer this over destination_overview, destination_listings, or the venue_* siblings. No exclusions or prerequisites are given, so the agent must infer routing.

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