Travel times between places

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

Annotations already declare readOnly, idempotent, non-destructive and openWorld, so safety is covered. The description adds real operational context beyond them: the geography restriction (India only), the mode-dependent behaviour (traffic allowance for drive), and a warning when a point is far from any road. That warning behaviour is not derivable from the schema or annotations.

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?

Two sentences, front-loaded with the core capability, then the input formats, outputs, and scope exclusions. No filler; every clause carries information an agent needs.

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?

With an output schema present, the description need not enumerate return fields, yet it still summarises the four returned metrics and the road-proximity warning. Combined with the India-only scope and mode options, an agent has everything needed to call this 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%, so each field (mode enum, lat/lng bounds, iata/station_code patterns, place resolution, per-list max items) is fully documented in the schema itself. The description restates the input formats ('lat+lng, a railway station code, an airport IATA code or a place name') but adds no syntax or constraint detail beyond what is already given. Baseline 3 applies.

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 (computes road distance and travel time) plus the scope (matrix from each origin to each destination in India) and mode (by car or on foot). An agent can immediately tell this is an origin-destination routing tool, distinct from the hotel-focused siblings and from resolve_place, which only geocodes single points.

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 supplies a when-not clause ('Does not cover public transport or flights'), which usefully prevents misuse, but gives no explicit when-to-use trigger and does not name an alternative such as resolve_place for single-point geocoding. Usage is implied (trip planning / matrix comparisons) rather than stated.

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