drive_time

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

With no annotations, the description carries full burden. It discloses data source (OSM), that duration is free-flow without live traffic, the computation of leaveByLocal when arriveBy is given, and the buffer mechanism. However, it does not mention error handling (e.g., place not found) or any rate limits.

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 one paragraph of 4–5 sentences, front-loaded with the core purpose, followed by input/output details and a critical caveat. Every sentence adds value without fluff.

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 no output schema, the description covers return values (distanceKm, durationMin, resolved place names, leaveByLocal) and explains the buffer and arrival parameters. It could mention potential errors (e.g., invalid place lookup) but is otherwise complete for a non-destructive routing tool.

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%, baseline 3. The description adds meaning beyond schema by providing example inputs for 'from'/'to', explaining the 'arriveBy' format (ISO datetime or HH:MM for today in Copenhagen), and detailing how 'bufferMin' is used in leaveByLocal calculation. This adds significant context.

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 states the tool computes car driving distance and typical travel time between two places in Denmark using OpenStreetMap data. It specifies the verb (compute), resource (distance and time), geographic scope (Denmark), data source (OSM), and output keys (distanceKm, durationMin, leaveByLocal). This is specific and distinguishes it from siblings like geocode.

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?

While the description implies the use case for driving time in Denmark and includes important caveats (no live traffic, rush hour allowance), it does not explicitly state when to use this tool versus siblings like geocode or leave_by. No verbal 'when-not' guidance or alternatives are given.

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