travel_stats

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

With no annotations, the description carries the full burden. It discloses the output metrics but not behavioral details such as how 'home' is defined, whether the tool is read-only, or any edge-case handling. The read-only nature is implied by the stats context but not stated.

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, front-loaded sentence that efficiently enumerates the key output categories. Every word adds value, and the structure makes it easy to scan.

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?

Given the absence of an output schema, the description does a good job listing the main output dimensions (kilometres by mode, flights, days away, countries/cities). It is reasonably complete for a simple stats tool, though it could clarify the definition of 'home' or the read-only nature.

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?

The schema provides full descriptions for all three parameters (since, until, period), so the description adds little beyond reinforcing that the tool looks at 'a period'. It does not clarify parameter interactions beyond what the schema already states.

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 defines what the tool does: it reports movement stats over a period, listing specific metrics (km by mode, flights, days away from home vs at home, countries/cities). This distinguishes it from sibling tools like cities_visited or trips, which provide detailed lists rather than aggregate statistics.

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 a use case (getting travel summary stats) but gives no explicit guidance on when to prefer this tool over alternatives or when not to use it. It does not mention that detailed trip-level info is available in 'trips' or that cities_visited/countries_visited provide raw lists.

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