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

Annotations only declare readOnlyHint=true; the description goes further by disclosing the response shape (slug, name, country, one line, last fact check, guide URL), which matters since there is no output schema. It omits pagination/result-count behavior, but for a small reference list that is a minor gap.

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 tight sentences with the resource definition front-loaded, then the hotel caveat, then the parameter note. The parenthetical field list is dense but earns its place by standing in for a missing output schema.

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 zero-required-parameter read tool with no output schema, the description covers what is returned, the one optional filter, and the key scope caveat about hotels. Only pagination or ordering behavior is left unspecified.

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%, so the baseline is 3. The description adds that q is optional and filters by name or country, but it drops 'slug', which the schema explicitly supports — a small loss of precision rather than added meaning.

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 names the resource (destination guides Quub has sourced) and enumerates the returned fields, so the agent knows exactly what this lists versus get_destination_guide (singular fetch). It never states the verb 'list' explicitly, relying on the name/title, but the scope is unmistakable.

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?

'Hotels can be searched anywhere, not only in these' is an explicit exclusion that steers the agent away from treating this as a hotel inventory filter, implicitly routing hotel queries to search_hotels. It stops short of naming the sibling or stating when to prefer get_destination_guide for a single entry.

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