cities_visited

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

With no annotations, the description carries the burden of behavioral disclosure. It discloses the return content (time in each city, number of separate visits, specific days), which is meaningful beyond the input schema. It does not mention read-only semantics explicitly, but no side effects are suggested.

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, information-dense sentence with a practical example, no redundancy.

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 query tool with four optional parameters and no output schema, the description covers the output fields and a concrete use case. It omits sort order and timezone handling, but the schema fills in parameter semantics.

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's 'over a period' loosely maps to since/until/period, but it adds no parameter-specific detail beyond what the schema already provides.

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 identifies the resource as cities visited within a time range and specifies the output dimensions (time spent, visit counts, days). The example 'which cities did I go to last spring' distinguishes it from sibling tools like countries_visited, though it lacks an explicit imperative verb.

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 provides a concrete use case ('Use for...'), giving clear context for when to select this tool. It does not name sibling alternatives or state exclusions, but the example is sufficient to signal appropriate use.

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