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

Annotations already declare readOnlyHint, idempotentHint, and destructiveHint, so the safety profile is covered. The description adds meaningful behavioral context beyond annotations: it reveals that the tool can report a destination as unavailable and exposes the alias relationship ('the destination's own host calls this get_overview').

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 a single dense sentence that front-loads the primary purpose, then appends a precise fallback instruction. Every clause contributes essential information, including the alias context, with no filler.

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 single-parameter, read-only tool with a full output schema and clear annotations, the description covers purpose, output contents, fallback behavior, parameter discovery, and alias context. Nothing critical is missing for an agent to invoke it 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?

Schema description coverage is 100%: the input schema already states 'Destination name or slug; call search_destinations to discover one.' The description's mention of 'named destination' and 'slug from search_destinations' reinforces but does not add new 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 uses a specific verb ('Get') with a clear resource ('named destination') and specifies the output ('summary: counts by category, currency, timezone'). It also distinguishes itself from get_destination by framing the latter as a fallback for unavailable destinations.

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?

It provides an explicit conditional fallback: if the destination is reported unavailable, use get_destination with the slug from search_destinations. This gives clear routing guidance for the common failure case, though it does not broadly contrast with other sibling tools like destination_listing or destination_faq.

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