maps_directions

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

No annotations are provided, so the description carries the full burden of behavioral disclosure. It conveys that the tool is a read operation returning route data, but it does not disclose the response structure (steps, durations, distances, polyline), whether multiple routes are possible, or any external API/network dependencies. For a tool with no output schema, this is thin.

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?

A single 9-word sentence that leads with the action, names the resource, and states both required inputs. There is no filler, repetition, or unnecessary formatting.

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?

The description gives an agent enough to select the tool and pass origin and destination, and 'turn-by-turn directions' hints at the response shape. However, with no output schema and no annotations, key context is missing: what the return object actually contains and when to choose this tool over maps_distance_matrix.

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%, with origin and destination format hints ('address, place name, or lat,lng') and the mode enum all documented inline. The description adds nothing beyond the parameter names themselves, so the schema does the heavy lifting and 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?

The description pairs a specific verb ('Get') with a specific resource ('turn-by-turn directions'), which clearly signals navigation instructions rather than distance/time metrics. This self-evidently differentiates it from siblings like maps_distance_matrix, maps_geocode, and maps_place_details without needing to name them.

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 use case is strongly implied: ask for step-by-step route instructions between two points. However, there is no explicit guidance on when to prefer this over maps_distance_matrix (for total time/distance without step-by-step maneuvers) or mention of any exclusions.

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