get_route_directions

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

With no annotations provided, the description discloses key behaviors: calculates the optimal route based on mode, returns distance/duration/maneuvers/geometry, and supports car/bike/foot modes. It clarifies that coordinates are in decimal degrees. It does not mention rate limits or error handling, but the core behavior is well covered.

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 well-structured with a summary, Args, and Returns sections, and it front-loads the purpose. It is slightly verbose with phrases like 'between any two locations on Earth,' but the structure makes it easy to parse and the content is relevant.

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 tool with no annotations and no output schema, the description provides parameter semantics, return value details, and use cases. It lacks explicit error handling or regional availability notes, but overall it gives an agent enough context to select and invoke the tool 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 0%, so the description compensates by explaining every parameter: coordinates as decimal degrees and the mode options with the default 'car'. This adds significant meaning beyond the bare schema property names and types.

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 'Calculate detailed route directions between two geographic points,' which is a specific verb and resource. It distinguishes itself from sibling tools like geocoding and nearby search by focusing on turn-by-turn navigation.

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 provides clear use cases: 'Perfect for trip planning, navigation assistance, and commute analysis.' It doesn't explicitly mention when not to use it or alternatives, but the context is sufficient for an agent to understand the primary scenarios.

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