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

Annotations already declare readOnly, idempotent, and non-destructive, but the description adds behavior they cannot express: the tool returns data only and a successful call must be followed by render_destination_info so the place card renders. It also sets expectations about output content and redirects to place_url for the full page, which is real orchestration context.

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 default-tool statement and the render follow-up are front-loaded and easy to scan. There is mild redundancy: the generic-info examples are restated in 'Do not use get_destination_weather for those generic info asks', which partially repeats the weather boundary that follows. Cost is small relative to the routing value.

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?

An output schema exists, so return values need not be described, and annotations cover the safety profile. For a single-param read tool the remaining burden is routing and post-call choreography, both of which are addressed, including the mandatory render step and the resolve_destination prerequisite.

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% and the handle format is already documented, so the baseline would be 3. The description earns extra credit by adding meaning beyond the type: it names concrete handles (hanoi, paris, tokyo) and, more importantly, tells the agent to call resolve_destination first when only a city, country, or airport name is available — a constraint the schema does not encode.

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 Sorted on-the-ground facts for one destination handle') and immediately enumerates what comes back: brief, safety, currency, phone code, eSIM notes, taxi apps. It explicitly distinguishes itself from the closest siblings, get_destination_weather and resolve_destination, so an agent can route without opening any 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?

Gives explicit when-to-use triggers with example utterances, a prerequisite routing rule ('if you only have a city, country, or airport name, call resolve_destination first'), and named exclusions for both get_destination_weather and bookings. The weather boundary is spelled out in both directions (generic info vs. explicit forecast/climate asks).

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