Road drive time (minutes) and distance (km), one way, from one place to another. Each place is an address or {lat, lng}. Traffic isn't included. Places outside the routing network's coverage are refused with the region named.
| Name | Required | Description | Default |
|---|---|---|---|
| to | Yes | An address (text) or coordinates {lat, lng} | |
| from | Yes | An address (text) or coordinates {lat, lng} |
Changes observed during successful MCP inspections.
Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?
Annotations already cover the safety profile (readOnlyHint, openWorldHint, destructiveHint=false). The description adds genuinely useful behavior beyond that: traffic is excluded from the estimate, and out-of-coverage places are refused with the region named. Lacks auth/rate-limit context, but this is solid added value.
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, front-loaded with the core capability, then the format, then the caveats. Every sentence earns its place with 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 two-param, no-output-schema tool, the description covers return semantics (minutes, km, one-way), accepted input forms, a limitation (no traffic), and failure behavior (coverage refusal). An agent has everything needed to call it 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 coverage is 100%, so both parameters are fully documented in the schema. The description repeats the address-or-{lat,lng} form without adding syntax, validation, or ambiguity-resolution detail, so the 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+resource with units and scope: 'Road drive time (minutes) and distance (km), one way, from one place to another.' An agent can immediately tell this apart from geocode_address, nearest_technicians, or technician_route.
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?
Usage is implied by the purpose (compute point-to-point drive time/distance), and the traffic caveat narrows expectations. However, no siblings are named and there is no explicit when-to-use/when-not guidance despite many adjacent routing tools (technician_route, plan_day_routes, zones_for_location).
Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.
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